Troy Ounce to Kilogram Converter
Convert troy ounces to kilograms with our free online weight converter.
Quick Answer
1 Troy Ounce = 0.031103 kilograms
Formula: Troy Ounce × conversion factor = Kilogram
Use the calculator below for instant, accurate conversions.
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All conversion formulas on UnitsConverter.io have been verified against NIST (National Institute of Standards and Technology) guidelines and international SI standards. Our calculations are accurate to 10 decimal places for standard conversions and use arbitrary precision arithmetic for astronomical units.
Troy Ounce to Kilogram Calculator
How to Use the Troy Ounce to Kilogram Calculator:
- Enter the value you want to convert in the 'From' field (Troy Ounce).
- The converted value in Kilogram will appear automatically in the 'To' field.
- Use the dropdown menus to select different units within the Weight category.
- Click the swap button (⇌) to reverse the conversion direction.
How to Convert Troy Ounce to Kilogram: Step-by-Step Guide
Converting Troy Ounce to Kilogram involves multiplying the value by a specific conversion factor, as shown in the formula below.
Formula:
1 Troy Ounce = 0.0311035 kilogramsExample Calculation:
Convert 5 troy ounces: 5 × 0.0311035 = 0.155518 kilograms
Disclaimer: For Reference Only
These conversion results are provided for informational purposes only. While we strive for accuracy, we make no guarantees regarding the precision of these results, especially for conversions involving extremely large or small numbers which may be subject to the inherent limitations of standard computer floating-point arithmetic.
Not for professional use. Results should be verified before use in any critical application. View our Terms of Service for more information.
Need to convert to other weight units?
View all Weight conversions →What is a Troy Ounce and a Kilogram?
1 troy ounce = 31.1034768 grams (g) = 480 grains
The troy ounce (abbreviated "oz t", "ozt", or "t oz") is a unit of mass in the troy weight system, used exclusively for precious metals and gemstones. It differs significantly from the avoirdupois ounce used in everyday measurements.
Troy vs. Avoirdupois: Critical Distinction
| Unit | Grams | Use Cases | |----------|-----------|---------------| | Troy ounce | 31.1034768 g | Precious metals (gold, silver, platinum), gemstones, pharmaceuticals (historic) | | Avoirdupois ounce | 28.349523125 g | Food, body weight, general commerce | | Difference | +2.754 g (9.7% heavier) | Troy ounce is HEAVIER |
Critical for buyers: If someone sells you "1 ounce of gold" using avoirdupois ounces instead of troy ounces, you're getting 9.7% less metal than you paid for!
The Troy Weight System
Unlike the avoirdupois system (16 ounces = 1 pound), the troy system uses different ratios:
- 24 grains = 1 pennyweight (dwt)
- 20 pennyweights = 1 troy ounce (oz t)
- 12 troy ounces = 1 troy pound (lb t)
Paradox: The troy ounce is heavier than the avoirdupois ounce, BUT the troy pound (373.24 g) is lighter than the avoirdupois pound (453.59 g) because it contains only 12 ounces instead of 16!
Why Troy Ounces Persist
Despite global metrication, troy ounces remain dominant in precious metals for these reasons:
- Market convention: Centuries of gold/silver trading established price benchmarks in troy ounces
- Legal tender: U.S. Mint, Royal Canadian Mint, and others mint official coins in troy ounce denominations
- Futures contracts: COMEX gold contracts specify 100 troy ounces per contract
- LBMA standards: London Bullion Market Association requires troy ounce quotations
- Central banks: Gold reserves reported in troy ounces (e.g., Fort Knox holds 147.3 million oz t)
The kilogram (symbol: kg) is the base unit of mass in the International System of Units (SI). It is one of the seven SI base units and forms the foundation for measuring mass and weight in the metric system.
Modern Definition (2019): The kilogram is defined by fixing the numerical value of the Planck constant (h) to be exactly 6.62607015×10⁻³⁴ joule-seconds (J⋅s). This definition, adopted on May 20, 2019 (World Metrology Day), replaced the previous definition based on a physical artifact.
Key relationships:
- 1 kilogram = 1,000 grams (g)
- 1 kilogram = 1,000,000 milligrams (mg)
- 1 kilogram = 0.001 metric tons (tonnes)
- 1,000 kilograms = 1 metric ton
In terms of imperial/US customary units:
- 1 kilogram ≈ 2.20462 pounds (lb) - Convert kg to lb
- 1 kilogram ≈ 35.274 ounces (oz) - Convert kg to oz
- 1 kilogram ≈ 0.157 stones (st) - Convert kg to stones
Visual perspective (how heavy is it?):
- 1 kg ≈ Liter bottle of water
- 1 kg ≈ Small laptop or tablet
- 1 kg ≈ Bag of sugar
- 1 kg ≈ Two pineapples
- 5 kg ≈ Newborn baby
- 10 kg ≈ Small dog or cat
Important distinction: While "mass" and "weight" are scientifically different (mass is the amount of matter, weight is gravitational force), in everyday usage, kilograms measure what we commonly call "weight."
Convert between weight units: kilogram converter
Note: The Troy Ounce is part of the imperial/US customary system, primarily used in the US, UK, and Canada for everyday measurements. The Kilogram belongs to the metric (SI) system.
History of the Troy Ounce and Kilogram
Ancient and Medieval Origins (Pre-1500)
The word "ounce" derives from the Latin "uncia" (one-twelfth), reflecting the Roman system where 1 uncia = 1/12 of a libra (pound). The troy system's specific origins trace to Troyes, France, a major European trade city.
12th-15th centuries - Champagne Fairs: Troyes hosted international trade fairs where merchants from Italy, Flanders, England, and German states exchanged goods. Precious metals, spices, and textiles required standardized weights. The "Troyes weight" system emerged as a trusted standard for valuable commodities, particularly gold, silver, and gemstones.
Why "troy" not "avoirdupois"? Two parallel weight systems developed:
- Troy weights: For precious metals, spices, medicines (high-value, small quantities)
- Avoirdupois weights: For bulk goods like wool, grain, iron (from French "avoir de pois" = goods of weight)
English Standardization (1500-1800)
1527 - King Henry VIII standardization: Henry VIII officially defined troy weights for the English realm, establishing:
- 1 troy pound = 5,760 grains
- 1 troy ounce = 480 grains
- 1 grain = 64.79891 milligrams (based on barley grain weight)
1758 - British assay offices: The Goldsmiths' Company and assay offices in London, Birmingham, Sheffield, and Edinburgh used troy ounces exclusively for hallmarking gold and silver items. This reinforced troy ounces as the legal standard for precious metals in British commerce.
The Tower Pound obsolescence: England previously used the "Tower pound" for minting coins (5,400 grains), but troy weights (5,760 grains per pound) eventually replaced it in 1527, creating unified standards for bullion and coinage.
American Adoption (1776-1900)
1776-1792 - Early United States: American colonies inherited British troy standards. The early U.S. used Spanish silver dollars and British gold sovereigns, all measured in troy ounces.
1828 - U.S. Coinage Act: Congress officially adopted troy weights for all U.S. coinage. The Act specified:
- Gold dollar = 25.8 grains (1.672 g) of 90% gold
- Silver dollar = 412.5 grains (26.73 g) of 90% silver
- All coins measured in troy grains
1849-1855 - California Gold Rush: The discovery of gold at Sutter's Mill created massive demand for standardized weights. Assay offices in San Francisco weighed gold dust and nuggets in troy ounces, establishing the unit in the American West.
1873 - Coinage Act ("Crime of 1873"): This act demonetized silver, ending bimetallism. However, troy ounces remained the standard for measuring both gold and silver bullion.
Global Standardization (1900-Present)
1900-1971 - The Gold Standard era: Most nations tied currencies to gold reserves, measured in troy ounces:
- 1900: Gold Standard Act (U.S. fixed $20.67 per troy ounce)
- 1933: FDR revalued gold to $35 per troy ounce
- 1944: Bretton Woods Agreement ($35/oz t peg)
- 1971: Nixon ended gold convertibility, but troy ounce pricing persisted
1919 - London Bullion Market Association (LBMA): Founded to standardize London gold market practices. LBMA established:
- Good Delivery bars: 350-430 troy ounces (typically 400 oz t)
- Minimum purity: 995 parts per 1,000 (99.5% pure gold)
- Troy ounce quotations for spot prices
1974 - COMEX gold futures: The Commodity Exchange (COMEX) in New York launched gold futures contracts:
- Contract size: 100 troy ounces
- Delivery specifications: 1 kg bars (32.1507 oz t) or 100 oz bars
- Global price discovery mechanism
1975 - Gold ownership legalization: U.S. citizens regained the right to own gold bullion (banned since 1933). Investment coins like the Krugerrand (1 oz t), Canadian Maple Leaf (1 oz t), and American Gold Eagle (1 oz t) popularized troy ounce denominations for retail investors.
2000s-Present - Digital age: Despite metrication, troy ounces dominate:
- ETFs: SPDR Gold Shares (GLD) holds 900+ tons (28.9M oz t)
- Central banks: Reserve holdings reported in troy ounces (U.S. 261.5M oz t, Germany 108.9M oz t)
- Spot prices: Bloomberg, Reuters, Kitco quote gold/silver per troy ounce
- Refineries: Swiss refiners (PAMP, Valcambi) produce bars in troy ounce sizes
Cultural Significance
The troy ounce represents continuity in global finance—a medieval trade standard that survived the industrial revolution, world wars, and digital transformation. While most historical units vanished with metrication, the troy ounce persists because precious metals markets value tradition, legal precedent, and universal standardization over decimal convenience.
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French Revolution Origins (1795): During the development of the metric system, French scientists defined the "grave" (later renamed kilogram) as the mass of one cubic decimeter (liter) of pure water at 4°C (its maximum density). This provided a definition based on nature rather than arbitrary standards.
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Kilogram des Archives (1799): The first physical standard was created - a platinum cylinder kept in the French National Archives in Paris. This "Kilogram of the Archives" served as France's official kilogram standard.
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Treaty of the Metre (1875): Seventeen nations signed this international treaty, establishing global cooperation on measurement standards. This set the stage for creating an international kilogram prototype.
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International Prototype Kilogram - Le Grand K (1889): A precisely machined platinum-iridium (90% platinum, 10% iridium) cylinder was created and designated as the international standard. This cylinder, known as "Le Grand K" or the IPK, was:
- 39 millimeters in both height and diameter
- Stored under three nested bell jars at the BIPM in Sèvres, France
- The only SI unit still defined by a physical artifact (until 2019)
- Accessed only rarely for calibration purposes
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The Problem with Le Grand K: Over time, scientists discovered that the IPK's mass was changing relative to its copies - by approximately 50 micrograms over a century. This was problematic because:
- The kilogram was drifting from its official definition
- No way to verify if the prototype was gaining or losing mass
- Physical objects can be damaged, contaminated, or lost
- Limited access meant difficult calibrations worldwide
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Search for a New Definition (1990s-2010s): Scientists developed two approaches:
- Kibble Balance (formerly watt balance): Relates mass to electromagnetic force and the Planck constant
- Avogadro Project: Count atoms in a silicon sphere to define the kilogram
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2019 Redefinition: On May 20, 2019 (World Metrology Day), the kilogram definition changed:
- Old: Mass of the International Prototype Kilogram
- New: Defined by fixing the Planck constant at exactly 6.62607015×10⁻³⁴ J⋅s
- This allows any properly equipped laboratory to reproduce the kilogram
- No longer depends on a physical object that could change or be damaged
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Why the Planck Constant?: This quantum mechanical constant relates energy to frequency and appears in fundamental physics equations. By fixing its value, mass can be measured using electromagnetic force through a Kibble balance.
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Global Impact: The kilogram is used by virtually every country worldwide. Even the United States, which uses pounds in daily life, uses kilograms extensively in:
- Scientific research
- International trade
- Medical dosing
- Manufacturing
- Athletics and sports
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Historical Significance: The 2019 redefinition was the culmination of over a century of metrological advancement, representing humanity's shift from physical artifacts to universal physical constants.
Common Uses and Applications: troy ounces vs kilograms
Explore the typical applications for both Troy Ounce (imperial/US) and Kilogram (metric) to understand their common contexts.
Common Uses for troy ounces
1. Precious Metals Trading
The troy ounce is the universal standard for global bullion markets:
Spot price quotations:
- Gold: $1,800-2,100 per troy ounce (fluctuates with markets)
- Silver: $20-30 per oz t
- Platinum: $900-1,200 per oz t
- Palladium: $1,000-1,600 per oz t
- Rhodium: $3,000-15,000 per oz t (highest volatility)
Major markets:
- London Bullion Market (LBMA): Sets gold/silver fix twice daily in troy ounces
- COMEX (New York): Futures contracts (100 oz t gold, 5,000 oz t silver)
- Shanghai Gold Exchange: Trades gold in grams but converts to oz t for international quotes
- Dubai Gold Souk: Retail sales in grams, wholesale in troy ounces
Why troy ounces persist: Centuries of price history, legal contracts, and central bank reserves create network effects—changing to grams would require recalibrating trillions in financial instruments.
2. Investment Coins & Bars
Government minted coins (1 oz troy):
- American Gold Eagle: Most popular U.S. bullion coin, 22K gold
- Canadian Maple Leaf: 24K gold (.9999 fine), iconic design
- South African Krugerrand: First modern bullion coin (1967)
- Austrian Philharmonic: European alternative, euro-denominated
- Chinese Gold Panda: Annual design changes, collector value
Fractional coins:
- 1/2 oz, 1/4 oz, 1/10 oz troy ounce denominations
- Higher premiums per ounce (manufacturing costs)
- Easier to liquidate small amounts
Private mint bars:
- 1 oz, 10 oz, 100 oz troy ounce sizes (silver)
- 1 oz, 10 oz, 1 kg gold bars
- Lower premiums than coins (no numismatic value)
- Stackability for storage
3. Jewelry Manufacturing
Jewelers purchase gold in troy ounces but often work in grams or pennyweights (dwt):
Pricing structure:
- Spot price: Current troy ounce price (e.g., $2,000/oz)
- Karat adjustment: 14K = 58.3%, 18K = 75%, 22K = 91.67%
- Fabrication cost: Labor, design, gemstones
- Retail markup: 2-3× material cost
Example calculation (14K ring):
- Weight: 5 grams = 0.16075 oz t
- Pure gold: 0.16075 × 0.583 = 0.0938 oz t
- Gold value: 0.0938 × $2,000 = $187.60
- Retail price: $500-800 (includes labor, overhead, profit)
Scrap gold recycling: Jewelers sell scrap in troy ounces to refineries, receiving 90-95% of spot price (refining losses, processing fees).
4. Pharmaceutical & Apothecary (Historic)
Before metrication, pharmacists used troy weights for compounding:
Apothecaries' system:
- 20 grains = 1 scruple
- 3 scruples = 1 dram
- 8 drams = 1 troy ounce
Modern legacy:
- Grain measurements persist (aspirin: 5 grains = 325 mg)
- Troy ounces phased out in medicine by 1970s
- Replaced by milligrams and grams for precision
5. Mining & Geology
Gold production and ore grades measured in troy ounces:
Reserve reporting:
- Gold deposits: "10 million oz t at 2 g/t grade" (metric tons ore, troy ounces gold)
- Production rates: "500,000 oz t per year" (annual mine output)
Ore grades:
- High-grade: 10-20 g/t (0.32-0.64 oz t per metric ton ore)
- Low-grade: 1-5 g/t (0.032-0.16 oz t/t)
- Ultra-low-grade: 0.5 g/t (economical with modern extraction)
Example (Nevada Gold Mine):
- Reserves: 50 million metric tons
- Grade: 2 g/t (0.064 oz t/t)
- Contained gold: 3.2 million troy ounces
- Mine life: 15 years (213,000 oz t/year production)
6. Central Banking & Reserves
Countries hold gold reserves measured in troy ounces:
Reserve valuation: Most central banks value gold at historic cost ($42.22/oz t, a 1973 price), not market rates. However, market value uses current spot prices:
- U.S. reserves: 261.5M oz t × $2,000 = $523 billion market value
- Official books: 261.5M oz t × $42.22 = $11 billion (!)
Reserve diversification:
- Gold as % of reserves: U.S. (70%), Germany (67%), Italy (64%)
- Rationale: Inflation hedge, currency crisis protection, geopolitical insurance
7. Collectibles & Numismatics
Coin collectors distinguish between bullion value (troy ounces) and numismatic value (rarity, condition):
Example: 1933 Double Eagle
- Gold content: 0.9675 oz t (~$1,935 melt value)
- Auction price: $18.9 million (2021 Sotheby's)
- Numismatic premium: 9,700× bullion value!
Modern bullion vs. collectible:
- Bullion: Trades at spot + 3-10% premium (1 oz Gold Eagle)
- Collectible: Rare dates, low mintages command 2-100× premiums
When to Use kilograms
The kilogram is the universal standard for mass measurement across virtually all applications worldwide:
Science and Research
The fundamental unit for mass in all scientific disciplines. Essential for chemistry, physics, biology, medicine, and engineering research conducted globally.
Scientific Applications:
- Chemistry: Measuring reactants, products, and samples
- Physics: Mass calculations in mechanics and dynamics
- Biology: Specimen weights, culture media
- Medicine: Drug dosing, patient measurements
- Materials science: Sample preparation and analysis
- Environmental science: Pollution measurements, soil samples
Why kilograms in science:
- SI base unit (international standard)
- Decimal-based for easy calculations
- Defined by fundamental constant (Planck constant)
- Required for publication in scientific journals
- Universal reproducibility in any laboratory
Convert for scientific work: kilograms to other units
Healthcare and Medicine
Standard for patient weight, drug dosing, and medical calculations in hospitals and clinics worldwide. Critical for accurate treatment.
Medical uses:
- Patient weight: Baseline health measurement
- Drug dosing: Many medications dosed per kg body weight
- Pediatric care: Growth charts in kg and cm
- BMI calculation: Weight (kg) ÷ height² (m)
- Fluid management: IV fluids calculated by body weight
- Nutritional assessment: Protein needs, calorie requirements
- Medical research: Study participant measurements
Dosing examples:
- Pediatric antibiotics: 10-15 mg per kg body weight
- Anesthesia: Calculated per kg
- Chemotherapy: Often dosed per kg or body surface area
- Emergency medications: Weight-based dosing critical
Why critical in medicine:
- Precision prevents overdosing or underdosing
- International medical protocols use kg
- Pediatric safety depends on accurate weights
- Research requires standardized measurements
Food Industry and Nutrition
Standard unit for food packaging, recipes, nutritional labels, and commercial food sales in metric countries and international trade.
Food industry uses:
- Packaging labels: "Net weight: 1 kg"
- Commercial sales: Produce sold per kg
- Nutritional information: Values per 100g or serving
- Recipe scaling: Professional cooking in kg
- Food safety: Portion control, serving sizes
- Import/export: International food trade
- Restaurant supplies: Ingredients ordered in kg
Retail examples:
- Fruits and vegetables: Priced per kg
- Meat and fish: Sold by kg or portion
- Bulk foods: Rice, flour, nuts sold in kg bags
- Deli counters: Sliced meats weighed in kg
Shipping and Logistics
International standard for package weight, freight calculations, and postal rates. Essential for global commerce and transportation.
Shipping applications:
- Package weight limits: Carriers specify max kg
- Freight charges: Calculated per kg or dimensional weight
- Postal rates: Tiered by kg (0-2 kg, 2-5 kg, etc.)
- Air cargo: Charged per kg
- Container shipping: Weight limits in kg
- Customs declarations: Product weights in kg
- Warehouse inventory: Stock measured in kg
Standard limits:
- Small parcel: Up to 2 kg
- Standard parcel: 2-20 kg
- Heavy parcel: 20-30 kg
- Freight: 30+ kg
Why kg in shipping:
- International standard (UPU uses kg)
- Simplifies cross-border shipping
- Aviation industry uses kg
- Maritime shipping uses metric tons (1,000 kg)
Athletics and Sports
Standard for athlete weight classes, equipment specifications, and performance measurements in international competition.
Weight classes (examples):
- Boxing: Flyweight (< 51 kg), Welterweight (< 69 kg), Heavyweight (> 91 kg)
- Wrestling: Multiple classes from 57 kg to 125 kg
- Weightlifting: Classes from 55 kg to 109+ kg
- MMA: Featherweight (66 kg), Middleweight (84 kg), etc.
- Rowing: Lightweight (< 72.5 kg men, < 59 kg women)
- Judo: Multiple classes from 60 kg to 100+ kg
Equipment standards:
- Shot put: 7.26 kg (men), 4 kg (women)
- Discus: 2 kg (men), 1 kg (women)
- Javelin: 800 g (men), 600 g (women)
- Hammer throw: 7.26 kg (men), 4 kg (women)
Performance metrics:
- Clean and jerk records (kg lifted)
- Total weight lifted in competitions
- Body composition tracking
Manufacturing and Industry
Critical for quality control, material specifications, and product development. Enables consistent production and international standards.
Manufacturing uses:
- Raw materials: Ordered and inventoried in kg
- Product specifications: Component weights in kg or grams
- Quality control: Weight tolerance checking
- Batch production: Recipe scaling by kg
- Packaging: Box and pallet weights
- Shipping calculations: Product + packaging weight
- Waste management: Scrap material measured in kg
Industries:
- Automotive: Vehicle weight specifications
- Aerospace: Critical weight calculations
- Pharmaceuticals: Active ingredient quantities
- Chemicals: Formulation by weight
- Textiles: Fabric weight per square meter (GSM)
Agriculture and Farming
Standard for crop yields, animal weights, feed quantities, and agricultural commodities worldwide.
Agricultural uses:
- Crop yields: Tons per hectare (1,000 kg = 1 ton)
- Livestock weights: Animal growth tracking
- Feed calculations: Feed ratios per kg body weight
- Fertilizer application: kg per hectare
- Produce sales: Market prices per kg
- Seed quantities: Planting rates in kg/hectare
- Harvest records: Total yield in kg or tons
Example yields:
- Wheat: 3,000-8,000 kg/hectare
- Corn: 5,000-12,000 kg/hectare
- Rice: 4,000-10,000 kg/hectare
Everyday Life (Metric Countries)
Daily measurements for body weight, shopping, cooking, and general household use in 95% of the world's countries.
Personal use:
- Body weight tracking (bathroom scale)
- Grocery shopping (price per kg)
- Cooking and baking (recipe measurements)
- Luggage weight (travel)
- Baby weight monitoring (growth charts)
- Fitness tracking (weight loss/gain goals)
- Pet weight (veterinary care)
Use our kilogram converter for everyday conversions.
Additional Unit Information
About Troy Ounce (oz t)
1. Is a troy ounce the same as a regular ounce?
No. The troy ounce (31.1035 g) is about 9.7% heavier than the avoirdupois ounce (28.3495 g) used for food and general items.
Visual comparison:
- 1 troy ounce gold = Size of a large grape (but very dense)
- 1 avoirdupois ounce flour = Same volume but less mass
When it matters: Precious metals (gold, silver, platinum) always use troy ounces. If someone offers you "1 ounce of gold" at a suspiciously low price, verify it's troy ounces—not avoirdupois!
2. How many grams are in a troy ounce?
Exactly 31.1034768 grams.
This precise definition comes from the 1959 international agreement on units. It's the same globally—LBMA (London), COMEX (New York), and Shanghai Gold Exchange all use this exact conversion.
For practical purposes:
- 1 troy oz ≈ 31.1 grams (rounded)
- 10 troy oz ≈ 311 grams
- 32.15 troy oz = 1 kilogram (exactly 1,000 g)
3. How many troy ounces are in a troy pound?
12 troy ounces = 1 troy pound (373.24 grams).
This differs from the avoirdupois system where 16 ounces = 1 pound. The troy system uses base-12 (duodecimal), a remnant of Roman and medieval counting systems.
Paradox explained:
- Troy ounce (31.10 g) > Avoirdupois ounce (28.35 g)
- BUT Troy pound (373.24 g) < Avoirdupois pound (453.59 g)
Why: 12 × 31.10 = 373.24, while 16 × 28.35 = 453.59.
4. Why do precious metals use troy ounces instead of grams?
Historical inertia and market convention.
Reasons troy ounces persist:
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Centuries of price data: Gold has been priced per troy ounce since the 1700s. Changing would break historical charts and analysis.
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Legal tender and contracts: U.S. Mint, Canadian Mint, and others legally define coins in troy ounces. Futures contracts, options, and derivatives are denominated in oz t.
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Central bank reserves: Fort Knox holds "147.3 million troy ounces," not "4,582.7 metric tons"—the legal records use troy ounces.
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Network effects: If London uses oz t, New York must too. Shanghai converts grams to oz t for international quotes.
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Cultural identity: "An ounce of gold" evokes tangibility. "31.1 grams of gold" lacks the same resonance.
Metrication attempts failed: France and other metric-first countries tried quoting gold in grams, but international traders kept converting back to oz t for comparison.
5. How much is 1 troy ounce of gold worth?
It fluctuates constantly. As of 2024, gold trades between $1,800 - $2,100 per troy ounce, depending on economic conditions.
Price drivers:
- Inflation fears: Gold rises when currency value erodes
- Interest rates: Low rates → gold attractive (no yield anyway)
- Geopolitical crises: Wars, sanctions boost safe-haven demand
- Central bank buying: China, Russia, Turkey accumulating reserves
- Jewelry demand: India, China seasonal festivals
Historical context:
- 1900: $20.67/oz (Gold Standard Act)
- 1971: $35/oz (Nixon Shock, end of Bretton Woods)
- 1980: $850/oz (Hunt Brothers silver crisis, inflation)
- 2011: $1,900/oz (Financial crisis aftermath)
- 2020: $2,067/oz (COVID-19 pandemic peak)
Real-time prices: Check Bloomberg, Reuters, Kitco, or bullion dealer sites.
6. What's the difference between "carat" and "karat"?
Completely different units—one measures weight, the other purity:
CARAT (ct) = Gemstone weight
- 1 carat = 200 milligrams = 0.00643 troy ounces
- Measures diamonds, rubies, sapphires, emeralds
- "5-carat diamond" = 1 gram weight
KARAT (K or kt) = Gold purity
- 24K = 100% pure gold
- 18K = 75% gold (18/24)
- 14K = 58.3% gold (14/24)
- Measures alloy composition, not weight
Example: "18K gold ring weighing 0.2 troy ounces" means:
- Karat: 75% pure (18/24)
- Weight: 0.2 oz t = 6.22 g total
- Pure gold: 0.15 oz t = 4.67 g (6.22 × 0.75)
7. Can I buy fractional troy ounces?
Yes! Governments and private mints produce fractional coins:
Common sizes:
- 1/10 oz t (3.11 g) — Popular for small investors
- 1/4 oz t (7.78 g)
- 1/2 oz t (15.55 g)
- 1 oz t (31.10 g) — Most popular size
Trade-offs:
- Pros: Lower entry cost ($200 for 1/10 oz vs. $2,000 for 1 oz), easier to liquidate small amounts
- Cons: Higher premiums per ounce (1/10 oz costs ~15% premium vs. 3-5% for 1 oz)
Example:
- 1 oz Gold Eagle: $2,050 ($50 premium over $2,000 spot = 2.5%)
- 1/10 oz Gold Eagle: $240 ($40 premium over $200 spot = 20%!)
Why higher premiums? Minting costs don't scale linearly. Striking a 1/10 oz coin costs almost as much as a 1 oz coin, so the percentage premium is higher.
8. What is a "Good Delivery" gold bar?
The international standard for large-scale gold bullion, set by the London Bullion Market Association (LBMA).
Specifications:
- Weight: 350-430 troy ounces (typically 400 oz t = 12.4 kg)
- Purity: Minimum 995 parts per 1,000 (99.5% pure gold)
- Fineness stamp: Refinery mark, serial number, purity, year
- Refiners: LBMA-approved list (~70 refineries: PAMP, Valcambi, Rand, Johnson Matthey)
Why "Good Delivery"? Before standardization, banks had to assay every bar (costly, time-consuming). LBMA Good Delivery certification means bars are universally accepted without re-assaying.
Where they're used:
- Central bank reserves (Fort Knox, Bank of England vaults)
- Commercial bank vaults (HSBC, JPMorgan)
- ETF backing (SPDR Gold Shares stores Good Delivery bars)
Retail availability: Most investors never see Good Delivery bars—they're institutional. Retail investors buy 1 oz coins or small bars (1 oz, 10 oz, 100 oz).
9. How do I convert troy ounces to kilograms?
Formula:
1 troy ounce = 0.0311034768 kilograms
OR
1 kilogram = 32.1507466 troy ounces
Quick method: Divide troy ounces by 32.15 to get kilograms:
400 oz t ÷ 32.15 ≈ 12.44 kg
Precise method: Multiply troy ounces by 0.0311034768:
400 oz t × 0.0311034768 = 12.44139072 kg (EXACT)
Common conversions:
- 1 oz t = 0.0311 kg
- 10 oz t = 0.311 kg
- 100 oz t = 3.11 kg
- 1,000 oz t = 31.1 kg
- 32.15 oz t = 1 kg (exactly 1,000 g)
10. What's the smallest amount of gold I can buy?
Technically, you can buy any amount, but practical minimums exist:
Physical gold:
- Smallest coins: 1/10 oz t (~$200-250)
- Gold jewelry: Varies, but 14K chains start around $100-200 (contains ~0.05 oz t pure gold)
- Gold leaf: Decorative, negligible weight (~0.001 oz t per sheet)
Paper gold (no physical delivery):
- Gold ETFs (GLD, IAU): 1 share ≈ 0.1 oz t (~$200)
- Fractional platforms (OneGold, Vaulted): Buy as little as $1 worth (0.0005 oz t)
- Futures contracts: 100 oz t minimum (~$200,000—professional traders only)
Recommendation for beginners: Start with 1/4 oz or 1/2 oz coins (balance between affordability and premiums). Avoid tiny fractions (1/20 oz) due to extremely high premiums.
11. How do jewelers measure gold?
Three units, depending on context:
- Troy ounces (oz t): Buying gold from refineries, calculating melt value
- Pennyweights (dwt): Traditional unit (1 oz t = 20 dwt, 1 dwt = 1.555 g)
- Grams (g): Modern standard, easier math
Example (jeweler selling 14K scrap):
- Weighs scrap: 25.5 grams
- Converts to troy ounces: 25.5 ÷ 31.1 = 0.82 oz t
- Calculates pure gold: 0.82 × 0.583 (14K) = 0.478 oz t
- Refinery pays: 0.478 × $2,000 × 0.95 = $908 (95% of spot, 5% refining fee)
Pennyweight legacy: Older jewelers still use "dwt" for historic reasons. Most modern shops use grams for precision.
12. Why are central banks buying more gold?
Diversification away from the U.S. dollar and geopolitical hedging.
Key drivers:
- De-dollarization: Russia, China, Turkey reducing USD reserves after sanctions
- Inflation hedge: 2020-2024 inflation spikes drove safe-haven demand
- Currency debasement fears: Massive money printing (COVID stimulus) erodes fiat value
- Geopolitical tensions: Ukraine war, Taiwan tensions increase reserve gold holdings
Recent trends (2020-2024):
- China: Added 300+ tons (9.6M oz t) in 2023 alone
- Russia: Doubled reserves to 2,300 tons (74M oz t) before Ukraine war
- Poland: Increased from 103 to 228 tons (7.3M oz t)
- Singapore: Tripled reserves to 230 tons (7.4M oz t)
Why troy ounces matter: Central bank transactions are reported in troy ounces (IMF, World Gold Council standards), even though storage is often measured in metric tons.
About Kilogram (kg)
How much is 1 kilogram visually?
One kilogram is about the weight of a liter bottle of water or a small laptop.
Visual comparisons:
- 1 liter of water: Exactly 1 kg (at 4°C)
- Bag of sugar: Typically 1 kg or 2 kg
- Small laptop: 1-1.5 kg
- Two pineapples: About 1 kg total
- Medium-sized book: Approximately 1 kg
- Loaf of bread: About 0.5-0.8 kg (1 kg for larger loaves)
Body reference:
- For most people, 1 kg is slightly heavier than can be easily held in one hand for extended periods
- About 2-3% of average adult body weight
To remember: Picture a standard milk or water bottle (1 liter) - that's 1 kilogram.
How many pounds are in a kilogram?
One kilogram equals approximately 2.20462 pounds, commonly rounded to 2.2 pounds.
Exact conversion: 1 kilogram = 2.204622622 pounds
Practical conversions:
- 1 kg ≈ 2.2 lb
- 5 kg ≈ 11 lb
- 10 kg ≈ 22 lb
- 50 kg ≈ 110 lb
- 70 kg ≈ 154 lb
- 100 kg ≈ 220 lb
Reverse conversion (pounds to kilograms):
- 1 pound = 0.453592 kg (about 0.45 kg)
- 10 pounds ≈ 4.5 kg
- 100 pounds ≈ 45.4 kg
- 150 pounds ≈ 68 kg
- 200 pounds ≈ 90.7 kg
Quick mental math:
- Multiply kg by 2 and add 10% for rough estimate
- Example: 50 kg × 2 = 100, + 10% = 110 lb
Use our kg to pounds converter for accurate conversions.
What is the difference between kilogram and gram?
Kilogram (kg) is 1,000 times larger than gram (g).
The relationship:
- 1 kilogram = 1,000 grams
- 1 gram = 0.001 kilograms (or 1/1,000 kg)
Conversion:
- To convert kg to g: multiply by 1,000
- To convert g to kg: divide by 1,000
When to use which:
Use grams (g) for:
- Small quantities (< 1 kg)
- Food ingredients (200g flour, 500g meat)
- Precious metals (gold, silver by the gram)
- Medications (pills in mg or g)
- Postal items under 1 kg
Use kilograms (kg) for:
- Body weight
- Larger food packages
- Most everyday objects
- Shipping packages
- Sports equipment
Examples:
- Smartphone: 200 grams = 0.2 kg
- Laptop: 1,500 grams = 1.5 kg
- Bag of rice: 5,000 grams = 5 kg
- Person: 70,000 grams = 70 kg
Convert: kg to grams | grams to kg
Is the kilogram used in the United States?
Yes and no - it depends on the context.
Where kilograms ARE used in the US:
- Science and research: All scientific work
- Medicine: Drug dosing, patient weights in hospitals
- Manufacturing: Especially export products
- Athletics: Olympic sports, international competition
- Import/export: International trade
- Automotive: Vehicle specifications (increasingly)
- Pharmaceuticals: All measurements
- Military: NATO standardization
Where kilograms are NOT commonly used:
- Grocery stores (pounds, not kg)
- Body weight (people say pounds)
- Cooking (recipes use cups, ounces)
- Bathroom scales (typically show pounds)
- Everyday conversation
- Food packaging (labeled in oz, lb)
The dual system:
- US products often show both: "1 lb (454g)" or "Net Wt 16 oz (1 lb) 453g"
- Scientific calculators and medical equipment use kg
- US is officially metric but hasn't converted fully
Fun fact: US currency is metric (100 cents = 1 dollar), but few Americans realize this!
How many grams are in a kilogram?
There are exactly 1,000 grams (g) in one kilogram.
Why 1,000?: The prefix "kilo-" means 1,000.
Conversion:
- 1 kilogram (kg) = 1,000 grams (g)
- To convert kg to g: multiply by 1,000
- To convert g to kg: divide by 1,000
Examples:
- 0.5 kg = 500 grams
- 1.5 kg = 1,500 grams
- 2.75 kg = 2,750 grams
- 5 kg = 5,000 grams
- 10 kg = 10,000 grams
Remember: Move the decimal point three places:
- Kg → g: Move right (1.5 kg = 1,500 g)
- G → kg: Move left (1,500 g = 1.5 kg)
Common weights:
- Smartphone: 150-250 g = 0.15-0.25 kg
- Bag of sugar: 1,000 g = 1 kg
- Newborn baby: 3,000-4,000 g = 3-4 kg
Use our kg to grams converter for instant conversions.
How is the kilogram defined today?
Current Definition (since May 20, 2019): The kilogram is defined by fixing the numerical value of the Planck constant at exactly 6.62607015×10⁻³⁴ joule-seconds (J⋅s).
What this means:
- No longer based on a physical object (the old platinum-iridium cylinder)
- Based on a fundamental constant of quantum mechanics
- Can be reproduced in any properly equipped laboratory worldwide
- Uses a device called a "Kibble balance" (formerly watt balance)
- Incredibly stable and will never change
Why this definition?:
- Universal: The Planck constant is the same everywhere in the universe
- Reproducible: Any lab with the right equipment can measure it
- Permanent: Physical objects degrade; constants don't
- Precise: More accurate than artifact-based definition
How it works: A Kibble balance measures mass by balancing it against electromagnetic force. By fixing the Planck constant, the electromagnetic force precisely defines mass.
Historical evolution:
- 1795: Mass of 1 liter of water
- 1889: Physical prototype (Le Grand K)
- 2019: Planck constant (current definition)
Why it matters: This was the last SI base unit to be redefined based on fundamental constants, completing the modernization of the metric system.
What does "kg" stand for?
"kg" is the symbol for kilogram.
Breaking it down:
- kilo-: Greek prefix meaning 1,000
- gram: Base unit of mass in the metric system
- kilogram: Literally "1,000 grams"
Symbol rules:
- Always lowercase "k" (not "Kg" or "KG")
- Lowercase "g"
- No period after "kg"
- Space between number and symbol: "5 kg" (not "5kg")
Other kilo- units:
- kilometer (km) = 1,000 meters
- kilowatt (kW) = 1,000 watts
- kilojoule (kJ) = 1,000 joules
- kilobyte (kB or KB) = 1,000 bytes
Interesting fact: The kilogram is unique among SI base units because it already contains a prefix ("kilo-"). The base unit is actually the gram, but kilogram is the official SI base unit for mass.
How do you convert kilograms to ounces?
To convert kilograms to ounces, multiply by approximately 35.274.
Conversion formula: ounces = kilograms × 35.274
Examples:
- 1 kg = 35.3 ounces
- 0.5 kg = 17.6 ounces
- 2 kg = 70.5 ounces
- 5 kg = 176.4 ounces
- 10 kg = 352.7 ounces
Reverse conversion (ounces to kilograms):
- 1 ounce = 0.0283495 kg (about 28.35 grams)
- 16 ounces (1 pound) = 0.4536 kg
- 32 ounces = 0.907 kg
- 100 ounces = 2.835 kg
Why 35.274?
- 1 kg = 2.20462 pounds
- 1 pound = 16 ounces
- 2.20462 × 16 = 35.274 ounces per kilogram
Quick mental math:
- 1 kg ≈ 35 oz (close enough for estimates)
- 0.5 kg ≈ 18 oz (just over 1 pound)
Use our kg to ounces converter for precise conversions.
What is 70 kg in pounds?
70 kilograms = 154.32 pounds (commonly rounded to 154 pounds).
Calculation: 70 kg × 2.20462 lb/kg = 154.32 lb
Context:
- Average adult: 70 kg is a typical weight for an average-height adult
- Healthy weight: For a 5'10" (178 cm) person, 70 kg is within healthy range
- Athletes: Many athletes in various sports weigh around 70 kg
Nearby conversions:
- 65 kg = 143 lb
- 70 kg = 154 lb
- 75 kg = 165 lb
- 80 kg = 176 lb
Body weight ranges (approximate):
- 50 kg = 110 lb (petite adult)
- 60 kg = 132 lb (average woman)
- 70 kg = 154 lb (average man)
- 80 kg = 176 lb (athletic/large build)
- 90 kg = 198 lb (large adult)
- 100 kg = 220 lb (very large adult)
Convert any weight: kg to pounds converter
How much does a kilogram weigh on Earth?
On Earth, 1 kilogram has a weight of approximately 9.8 newtons (N) at sea level.
Important distinction:
- Mass: 1 kilogram (constant everywhere)
- Weight: Force due to gravity = mass × gravitational acceleration
- On Earth: Weight (N) = 1 kg × 9.8 m/s² = 9.8 N
What this means:
- Your mass stays 1 kg everywhere
- Your weight changes based on gravitational strength
- On Earth, we feel this as "weight"
Weight on other celestial bodies (for 1 kg mass):
- Moon: 1.6 N (about 1/6 of Earth)
- Mars: 3.7 N (about 3/8 of Earth)
- Jupiter: 24.8 N (about 2.5× Earth)
- Sun: 274 N (about 28× Earth)
- International Space Station: ~8.7 N (microgravity, but not zero)
Why we say "weight in kilograms": In everyday language, "weight" means mass. Technically incorrect, but universally understood. Scientists use "mass in kilograms" and "weight in newtons" for precision.
Remember: Your bathroom scale measures mass (kg), not weight (newtons), but we casually call it "weight."
What is a metric ton vs kilogram?
Metric ton (also called tonne) = 1,000 kilograms.
The relationship:
- 1 metric ton = 1,000 kg
- 1 kilogram = 0.001 metric tons
Symbols:
- Metric ton: t or MT or tonne
- Kilogram: kg
When to use which:
Use kilograms (kg) for:
- Individual weights (< 1,000 kg)
- Body weight, packages, products
- Most everyday measurements
Use metric tons (tonnes) for:
- Heavy vehicles (cars, trucks)
- Industrial materials
- Bulk commodities
- Cargo shipping
- Agricultural yields
Examples:
- Small car: 1,000-1,500 kg = 1-1.5 metric tons
- Elephant: 5,000 kg = 5 metric tons
- Shipping container: 20,000-30,000 kg = 20-30 metric tons
- Wheat harvest: 100,000 kg = 100 metric tons
Confusion alert:
- Metric ton (1,000 kg) ≠ US ton (2,000 lb = 907 kg)
- Metric ton (1,000 kg) ≠ UK ton (2,240 lb = 1,016 kg)
- Always specify which ton!
Convert: kg to metric tons | metric tons to kg
Conversion Table: Troy Ounce to Kilogram
| Troy Ounce (oz t) | Kilogram (kg) |
|---|---|
| 0.5 | 0.016 |
| 1 | 0.031 |
| 1.5 | 0.047 |
| 2 | 0.062 |
| 5 | 0.156 |
| 10 | 0.311 |
| 25 | 0.778 |
| 50 | 1.555 |
| 100 | 3.11 |
| 250 | 7.776 |
| 500 | 15.552 |
| 1,000 | 31.104 |
People Also Ask
How do I convert Troy Ounce to Kilogram?
To convert Troy Ounce to Kilogram, enter the value in Troy Ounce in the calculator above. The conversion will happen automatically. Use our free online converter for instant and accurate results. You can also visit our weight converter page to convert between other units in this category.
Learn more →What is the conversion factor from Troy Ounce to Kilogram?
The conversion factor depends on the specific relationship between Troy Ounce and Kilogram. You can find the exact conversion formula and factor on this page. Our calculator handles all calculations automatically. See the conversion table above for common values.
Can I convert Kilogram back to Troy Ounce?
Yes! You can easily convert Kilogram back to Troy Ounce by using the swap button (⇌) in the calculator above, or by visiting our Kilogram to Troy Ounce converter page. You can also explore other weight conversions on our category page.
Learn more →What are common uses for Troy Ounce and Kilogram?
Troy Ounce and Kilogram are both standard units used in weight measurements. They are commonly used in various applications including engineering, construction, cooking, and scientific research. Browse our weight converter for more conversion options.
For more weight conversion questions, visit our FAQ page or explore our conversion guides.
Helpful Conversion Guides
Learn more about unit conversion with our comprehensive guides:
📚 How to Convert Units
Step-by-step guide to unit conversion with practical examples.
🔢 Conversion Formulas
Essential formulas for weight and other conversions.
⚖️ Metric vs Imperial
Understand the differences between measurement systems.
⚠️ Common Mistakes
Learn about frequent errors and how to avoid them.
All Weight Conversions
Other Weight Units and Conversions
Explore other weight units and their conversion options:
- Gram (g) • Troy Ounce to Gram
- Milligram (mg) • Troy Ounce to Milligram
- Pound (lb) • Troy Ounce to Pound
- Ounce (oz) • Troy Ounce to Ounce
- Stone (st) • Troy Ounce to Stone
- Ton (metric) (t) • Troy Ounce to Ton (metric)
- Ton (US) (ton) • Troy Ounce to Ton (US)
- Ton (UK) (long ton) • Troy Ounce to Ton (UK)
- Microgram (µg) • Troy Ounce to Microgram
- Carat (ct) • Troy Ounce to Carat
Verified Against Authority Standards
All conversion formulas have been verified against international standards and authoritative sources to ensure maximum accuracy and reliability.
National Institute of Standards and Technology — US standards for weight and mass measurements
International Organization for Standardization — International standard for mechanics quantities
Last verified: December 3, 2025