Stone to Ton (US) Converter
Convert stones to US tons with our free online weight converter.
Quick Answer
1 Stone = 0.007 US tons
Formula: Stone × conversion factor = Ton (US)
Use the calculator below for instant, accurate conversions.
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Stone to Ton (US) Calculator
How to Use the Stone to Ton (US) Calculator:
- Enter the value you want to convert in the 'From' field (Stone).
- The converted value in Ton (US) 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 Stone to Ton (US): Step-by-Step Guide
Converting Stone to Ton (US) involves multiplying the value by a specific conversion factor, as shown in the formula below.
Formula:
1 Stone = 0.007 US tonsExample Calculation:
Convert 5 stones: 5 × 0.007 = 0.035 US tons
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.
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View all Weight conversions →What is a Stone and a Ton (US)?
1 stone = 14 avoirdupois pounds (lb) = 6.35029318 kilograms (kg) EXACT
The stone (symbol: st) is a unit of mass in the Imperial system, legally defined in terms of pounds, which are themselves defined in terms of kilograms. The exact conversion is:
1 pound = 0.45359237 kilograms (international definition, 1959)
1 stone = 14 × 0.45359237 kg = 6.35029318 kg
Stone and Pounds Notation
The stone is almost never used alone for body weight. Instead, it's combined with additional pounds:
Format: "X stone Y pounds" or "X st Y lb"
Examples:
- 10 st 0 lb = 10 stone exactly = 140 lb = 63.5 kg
- 10 st 7 lb = 10 stone + 7 pounds = 147 lb = 66.7 kg
- 12 st 3 lb = 12 stone + 3 pounds = 171 lb = 77.6 kg
Why this format? It provides precision without unwieldy decimal places. Saying "10.5 stone" is rare—people say "10 stone 7" instead (10 stone + 7 pounds = 10.5 stone).
Stone vs. Kilogram vs. Pound
Three systems for measuring body weight:
| System | Unit | Used In | Precision | |-----------|----------|-------------|---------------| | Imperial (UK) | Stone + Pounds | UK, Ireland | "11 st 7 lb" (161 lb) | | Imperial (US) | Pounds only | United States, Canada | "161 lb" | | Metric | Kilograms | Most of the world | "73 kg" |
Cultural difference:
- Americans say "I weigh 161 pounds"
- British say "I weigh 11 stone 7" (rarely "161 pounds")
- Europeans say "I weigh 73 kilograms"
Why 14 Pounds?
The number 14 has no scientific basis—it's purely historical. Medieval England used base-12 counting (duodecimal) for some systems:
- 12 inches = 1 foot
- 12 pence = 1 shilling (pre-1971)
- But 14 pounds = 1 stone (not 12!)
Theory: The 14-pound wool stone emerged from trade practices. A "sack of wool" weighed 364 pounds = 26 stones (26 × 14 = 364), a convenient round number for taxation and commerce.
What Is a US Ton?
The US ton (officially called the short ton) is a unit of mass in the United States customary measurement system, defined as:
- Exactly 2,000 pounds (avoirdupois pounds)
- Exactly 32,000 ounces
- Exactly 907.18474 kilograms (by definition from 1959 international agreement)
- 20 hundredweight (where 1 hundredweight = 100 pounds in US system)
The US ton is the standard unit for measuring heavy loads in American commerce, transportation regulations, construction materials, and industrial applications.
US Ton vs. Metric: Key Comparison
US Ton (Short Ton):
- 2,000 pounds (exactly)
- 907.185 kilograms (907.18474 kg precisely)
- Used in United States for trucks, cargo, materials
- Based on 2,000-pound commercial standard
Metric Tonne:
- 1,000 kilograms (exactly)
- 2,204.623 pounds (about 2,205 lb)
- Global standard for international trade, shipping, emissions
- Based on metric system (1,000 kg)
Visual comparison:
- A metric tonne is about 92.8 kg heavier than a US ton (about 205 lb more)
- 1 metric tonne = 1.102 US tons (about 10% heavier)
- 1 US ton = 0.907 metric tonnes (about 10% lighter)
Commercial impact: A 20-ton truck in the US (40,000 lb) equals 18.14 metric tonnes. A 20-tonne truck in Europe (20,000 kg) equals 22.05 US tons. This distinction matters for international shipping, vehicle regulations, and trade contracts.
US Ton vs. Long Ton (UK)
US Ton (Short Ton):
- 2,000 pounds (20 hundredweight × 100 lb)
- 907.185 kg
- Standard in United States
Long Ton (Imperial Ton, UK):
- 2,240 pounds (20 hundredweight × 112 lb)
- 1,016.047 kg
- 12% heavier than US ton
- Used historically in UK, now largely replaced by metric tonne
Difference: The long ton is 240 pounds heavier than the US ton. This originated from different definitions of "hundredweight"—the US uses 100 lb, while the UK traditionally used 112 lb.
When it matters: Historical shipping documents, UK coal trade, and older engineering specifications may reference "tons" meaning long tons (2,240 lb), not US short tons (2,000 lb).
Note: The Stone is part of the imperial/US customary system, primarily used in the US, UK, and Canada for everyday measurements. The Ton (US) belongs to the imperial/US customary system.
History of the Stone and Ton (US)
Ancient and Medieval Origins (Pre-1300)
The concept of standardized stones: Before precise metallic weights, communities used stones as trade counterweights. A merchant would keep a reference stone in the marketplace, verified by local authorities, against which goods were weighed.
Advantages:
- Durability: Stones don't corrode or wear like metal
- Availability: Every village had stones
- Tamper-resistance: Hard to secretly shave weight off a stone
Problem: Every region had different stones! The "stone of wool" in Yorkshire differed from the "stone of wool" in Kent.
Medieval Standardization Attempts (1300-1824)
Edward III's wool stone (1340): King Edward III standardized the wool stone at 14 pounds as part of regulating the lucrative wool trade (England's economic backbone in the Middle Ages). The "sack of wool" was defined as 364 pounds = 26 stones.
Commodity-specific stones: Different goods had different stone weights:
| Commodity | Stone Weight | Reasoning | |--------------|-----------------|---------------| | Wool | 14 lb (6.35 kg) | Trade standard | | Meat | 8 lb (3.63 kg) | Butcher's stone | | Glass | 5 lb (2.27 kg) | Fragile goods | | Cheese | 16 lb (7.26 kg) | Agricultural products | | Iron | Variable (8-15 lb) | Regional differences |
Why different weights? Practical reasons:
- Heavy commodities (iron, lead): Smaller stone weight made counting easier
- Light, valuable goods (wool, spices): Larger stone weight reduced fractions
- Tradition: Each guild jealously guarded its customary weights
The Weights and Measures Act 1824
The problem: By 1800, Britain had dozens of incompatible stone definitions, creating chaos in trade and taxation.
The solution: The 1824 Act standardized British weights and measures:
- 14 pounds = 1 stone (for general use, not tied to specific commodities)
- Stone officially defined in relation to the pound
- Commodity-specific stones discouraged (but not banned)
Imperial standardization: The Act also defined:
- 1 pound = 7,000 grains
- 16 ounces = 1 pound
- 14 pounds = 1 stone
- 8 stone = 1 hundredweight (112 pounds)
- 20 hundredweight = 1 ton (2,240 pounds)
Body weight adoption: The Victorian era (1837-1901) saw the stone become the standard for human weighing. Bathroom scales, medical records, and public health data used stones and pounds.
Metrication and Persistence (1965-Present)
The Weights and Measures Act 1965: The UK officially adopted the metric system, making kilograms the legal unit for trade. However, the Act exempted personal weighing—bathroom scales could continue showing stones.
Why the exemption?
- Cultural resistance: Brits refused to abandon stones for body weight
- Economic lobbying: Scale manufacturers didn't want to retool
- Medical inertia: NHS records already used stones; conversion would be costly
The result: 60+ years later, the stone persists:
- Bathroom scales: Default to stones in the UK (even modern digital ones)
- NHS medical records: Still record patient weight in stones/pounds
- Weight loss programs: Slimming World, Weight Watchers UK use stones
- Media: British newspapers report celebrity weight in stones
- Sports: Boxing, horse racing, rowing use stones for weight classes
Ireland's experience: Ireland officially adopted metric units in 2005, but the stone remains common for body weight, especially among older generations.
Generational divide:
- Older Brits (60+): Think exclusively in stones
- Middle-aged (30-60): Bilingual (stones and kilograms)
- Younger (<30): Increasingly use kilograms, but still understand stones
Cultural Tenacity
The stone is the most persistent Imperial unit in British daily life, outlasting:
- Fahrenheit: Replaced by Celsius (weather, ovens)
- Inches/feet for height: Partially replaced by metres (though feet still common)
- Pints: Milk sold in litres (though beer still sold in pints!)
- Miles: Road signs still use miles (the UK never fully switched)
Why the stone survives:
- Emotional connection: Body weight is personal; changing units feels invasive
- Convenient range: For adults, weight is 8-20 stones (easy to remember vs. 50-127 kg)
- Medical exemption: Doctors use stones, so patients use stones
- Social reinforcement: Everyone around you uses stones, so you do too
Etymology: The "Tun" Wine Cask
The word "ton" derives from the medieval "tun," a large wine barrel or cask used for transporting and storing wine. A standard tun held approximately 252 wine gallons and weighed roughly 2,000 pounds when full.
This practical origin meant "ton" became synonymous with "very heavy load"—approximately the weight that could be carried in one tun cask. The measurement evolved from this real-world shipping container into a standardized unit of weight.
English Origins: Competing Ton Standards
In medieval and early modern England, multiple "ton" standards coexisted, creating confusion in commerce:
1. Wine Ton (Tun): ~2,000 pounds, based on wine cask weight 2. Long Ton: 2,240 pounds, based on 20 long hundredweight (20 × 112 lb) 3. Shipping Ton: Volume-based, used for calculating cargo space, not weight
The long ton (2,240 lb) became the official British standard, formalized in the British Imperial system in 1824. It was calculated as 20 hundredweight, where 1 hundredweight (cwt) = 112 pounds (8 stone × 14 lb/stone).
The short ton (2,000 lb) remained in common commercial use, especially in trades dealing with bulk commodities. It represented 20 hundredweight of 100 pounds each, a simpler rounding for everyday commerce.
American Adoption: The Short Ton (2,000 Pounds)
When American colonists inherited English measurement systems, both long ton (2,240 lb) and short ton (2,000 lb) were in use. After independence, the United States faced a choice between standardizing on one or the other.
Reasons the US chose the short ton (2,000 lb):
- Simpler arithmetic: 2,000 is easier to divide and calculate than 2,240
- Commercial preference: The 2,000-pound ton was already common in American trade
- Hundredweight definition: The US standardized on 100-pound hundredweight (rather than 112 lb), making 20 × 100 = 2,000 lb logical
- Decimal thinking: 2,000 fits better with base-10 calculations
In 1832, the US Treasury Department formally adopted the 2,000-pound ton as the standard US ton, distinguishing it as the "short ton" to differentiate from the British "long ton" (2,240 lb).
Metric Definition (1959)
The 1959 International Yard and Pound Agreement refined the US ton's definition in metric terms:
- 1 pound = 0.45359237 kilograms (exactly)
- 1 US ton = 2,000 pounds = 907.18474 kilograms (exactly)
This metric definition ended ambiguity about the ton's exact mass in international contexts and established clear conversion factors for trade between US customary and metric systems.
Modern Usage: Persistent in US, Metric Elsewhere
Today, the US ton remains dominant in American industry despite global metrication:
Why the US ton persists in America:
- Transportation regulations: Federal trucking regulations use tons (Gross Vehicle Weight Rating in tons)
- Construction pricing: Gravel, sand, concrete priced per ton (2,000 lb)
- Cultural inertia: Generations of American industry built around ton-based systems
- Equipment design: Trucks, scales, loading equipment calibrated in tons
Global trend toward metric tonnes:
- International shipping: Maritime cargo measured in metric tonnes (1,000 kg)
- Carbon emissions: Greenhouse gases measured in tonnes CO2 (metric)
- Scientific use: Research and engineering use metric tonnes exclusively
- Trade contracts: International agreements specify metric tonnes to avoid confusion
Result: The US is the only major economy still using short tons as the primary heavy-weight standard, requiring constant conversion for international commerce.
Common Uses and Applications: stones vs US tons
Explore the typical applications for both Stone (imperial/US) and Ton (US) (imperial/US) to understand their common contexts.
Common Uses for stones
1. Body Weight Measurement
The stone is the unit for body weight in the UK and Ireland.
Bathroom scales:
- Display: "11 st 7 lb" (digital) or analog dial with stone markings
- Dual units: Many scales toggle between st/lb and kg
- Default: Stones for UK-sold scales, even from international brands
Weighing yourself:
- British: "I'm 12 stone 3"
- American: "I'm 171 pounds"
- European: "I'm 78 kilograms"
Weight goals:
- "I want to lose a stone" = 14-pound goal
- "I'm aiming for 10 stone" = target weight
- "I've gained half a stone" = 7-pound increase
2. Medical and Healthcare
NHS patient records: British hospitals and GPs record weight in stones/pounds (with kg conversion).
Medical forms:
- Pre-op questionnaires: "Weight: __ st __ lb"
- Prescription dosing: Sometimes based on weight (converted to kg for calculations)
- Anesthesia planning: Weight in stones converted to kg for drug dosages
Maternity care:
- Booking appointment: "What was your pre-pregnancy weight?" (stones)
- Pregnancy weight tracking: "You've gained 2 stone, which is healthy"
- Post-natal: "Most women lose 1-2 stone in the first weeks"
Mental health context: Eating disorder treatment tracks weight changes in stones (e.g., anorexia recovery: "gained 1 stone to 7 stone 10").
3. Weight Loss and Fitness
Slimming clubs:
- Slimming World, Weight Watchers UK: Weigh-ins in stones
- Awards: "Half-stone hero," "Stone club," "3-stone milestone"
- Targets: "Lose 10% of body weight" (e.g., 1.5 stone from 15 stone start)
Fitness apps (UK versions):
- MyFitnessPal UK: Input weight in stones
- Fitbit/Garmin: UK users set goals in stones
- Weight tracking graphs: Y-axis shows stones, not kg
Personal trainers: British trainers discuss client progress in stones: "You've dropped from 14 stone to 12 stone 8—fantastic!"
4. Sports Weight Classes
Boxing: British boxing traditionally used stones for weight classes (now officially kilograms, but stones still common in commentary).
Horse racing:
- Jockey weights: Includes jockey + saddle + lead weights to meet required "riding weight"
- Handicapping: Horses carry different weights (in stones) to equalize competition
- Penalties: "Carrying 9 stone 7" vs. "Carrying 10 stone" affects race outcomes
Rowing: Lightweight rowers must weigh under certain stone limits (now metric, but historically stones).
5. Everyday Conversation
The stone pervades British informal speech:
Common phrases:
- "I'm 11 stone, give or take" = approximate weight
- "She must be 10 stone soaking wet" = very light
- "He's put on a stone since Christmas" = seasonal weight gain
- "I haven't been 9 stone since I was 15!" = nostalgic reference
Social etiquette:
- It's impolite to ask someone's weight directly, but acceptable to discuss your own
- Women might say "I'm trying to get back to 9 stone" (goal weight)
6. Media and Entertainment
British TV shows:
- Reality TV: "Love Island" contestants' weights discussed in tabloids (stones)
- Medical shows: "Embarrassing Bodies" references patient weight in stones
- Game shows: "The Biggest Loser UK" tracked loss in stones
Newspapers and magazines:
- Celebrity weight speculation: "Has she lost 2 stone?"
- Health articles: "How to lose half a stone by summer"
- Success stories: "I lost 8 stone and transformed my life!"
7. Historical and Cultural References
Literature: Victorian novels reference weight in stones:
- Dickens, Austen rarely mention specific weights (impolite)
- 20th-century literature: "She was a strapping girl of 12 stone"
British humor: Comedians joke about weight in stones:
- "I'm not overweight, I'm just undertall for my 14 stone!"
Generational markers:
- Older Brits: "When I got married, I was 8 stone"
- Modern comparison: "That's only 112 pounds—too thin by today's standards!"
When to Use US tons
1. Trucking and Transportation Regulations
Federal trucking regulations:
- Weight limits: Federal limit 80,000 lb (40 tons) gross vehicle weight on interstate highways
- Bridge formulas: Determine allowable weight based on axle spacing
- Weight stations: Weigh trucks to ensure compliance (fines for overweight)
Vehicle classification by GVWR:
- Class 1-2: Up to 10,000 lb (5 tons) — pickups, vans
- Class 3: 10,001-14,000 lb (5-7 tons) — heavy-duty pickups
- Class 4-6: 14,001-26,000 lb (7-13 tons) — box trucks, delivery trucks
- Class 7-8: 26,001-80,000 lb (13-40 tons) — semis, dump trucks, tractor-trailers
Commercial driver's license (CDL) requirements:
- CDL required: Vehicles over 26,000 lb (13 tons) GVWR
- Special endorsements: Hazmat, tanker, double/triple trailers
2. Construction and Building Materials
Material purchasing:
- Bulk materials: Gravel, sand, topsoil, mulch ordered by the ton
- Delivery trucks: 10-ton, 15-ton, 20-ton capacity standard sizes
- Pricing: Per-ton pricing typical ($20-$100/ton depending on material)
Structural engineering:
- Load calculations: Building load capacity measured in tons (tons per square foot)
- Crane capacity: Cranes rated by maximum lift capacity in tons (e.g., 50-ton crane)
- Equipment weight: Bulldozers, excavators specified by operating weight in tons
Concrete and cement:
- Ready-mix trucks: 8-10 cubic yard capacity (~16-20 tons wet concrete)
- Cement bags: 94 lb bags; ~21 bags = 1 ton cement
- Foundation loads: Structural loads calculated in tons
3. Waste Management and Environmental Services
Municipal solid waste:
- Collection fees: Often based on tonnage (residential flat fee, commercial per ton)
- Landfill tipping fees: $30-$100 per ton (varies by region, landfill type)
- Transfer stations: Weigh incoming waste by ton for billing and tracking
Recycling markets:
- Material pricing: Cardboard, metals, plastics traded by ton
- Scrap metal: Auto scrap, structural steel sold by ton to recyclers
- Commodity markets: Recycled materials priced per ton (fluctuates with demand)
Environmental reporting:
- Emissions: Industrial facilities report emissions in tons (NOx, SOx, PM)
- Waste reduction goals: "Divert 10,000 tons from landfills annually"
- Composting: Organic waste diverted measured in tons
4. Maritime and Port Operations
Cargo handling (US ports):
- Container weights: Listed in both tons (US) and metric tonnes (international)
- Crane capacity: Gantry cranes rated in tons lifting capacity
- Ballast water: Ship ballast measured in tons
Vessel tonnage (historical short ton use):
- Gross tonnage (GT): Volume-based ship size measurement (100 cubic feet = 1 register ton)
- Deadweight tonnage (DWT): Weight capacity, now primarily metric tonnes
- Displacement tonnage: Weight of water displaced, traditionally long tons, now metric
US domestic shipping:
- Great Lakes shipping: Often uses short tons for iron ore, coal, grain shipments
- Coastal shipping: Barge loads measured in tons
5. Industrial Manufacturing
Raw material purchasing:
- Steel, aluminum, copper: Purchased by the ton
- Chemicals: Bulk chemicals ordered in ton quantities
- Plastics: Resin pellets sold by ton
Production capacity:
- Steel mill: "Produces 2 million tons steel per year"
- Cement plant: "10,000 tons clinker production per day"
- Paper mill: "500 tons paper production per day"
Heavy machinery:
- Equipment weight: Specified in tons (e.g., "150-ton hydraulic press")
- Material handling: Forklifts, cranes rated by ton capacity
- Foundry operations: Ladle capacity measured in tons of molten metal
6. Agriculture and Commodity Trading
Crop production:
- Yield reporting: "Harvested 5,000 tons corn" or "200 bushels/acre"
- Storage: Grain elevators capacity measured in tons
- Trading: Commodity futures traded in tons or metric tonnes
Livestock operations:
- Feed consumption: "Dairy consumes 1,500 tons feed per year"
- Manure management: Measured in tons for spreading, composting
- Livestock hauling: Trailer capacity rated in tons
Farm equipment:
- Tractor weight: Specified in tons (affects traction, field compaction)
- Implements: Plow, harrow weight measured in tons
7. Energy and Mining
Coal industry:
- Mining production: Measured in tons per day/year
- Transportation: Coal trains (100+ cars × 100 tons = 10,000+ ton trains)
- Power generation: Plant fuel consumption measured in tons/day
Mining operations:
- Ore extraction: Production measured in tons mined per day
- Haul trucks: Mining dump trucks carry 100-400 tons per load
- Processing capacity: "Processes 50,000 tons ore per day"
Oil and gas (weight measurements):
- Equipment: Drilling rigs, platforms specified by weight in tons
- Offshore installations: Platform deck capacity measured in tons
Additional Unit Information
About Stone (st)
1. How many pounds are in a stone?
Exactly 14 pounds.
This is a defined constant. There are no regional variations—1 stone always equals 14 pounds in any context.
Calculation examples:
- 5 stone = 5 × 14 = 70 pounds
- 12 stone = 12 × 14 = 168 pounds
- 0.5 stone = 0.5 × 14 = 7 pounds
2. Is the stone used outside the UK and Ireland?
Rarely. The stone is almost exclusive to the UK and Ireland.
Usage by country:
- UK: Dominant for body weight (even with official metrication)
- Ireland: Common, especially among older generations
- Canada, Australia, New Zealand: Not used (fully metric)
- United States: Not used (pounds only)
- Rest of world: Not used (metric)
Exception: British expats abroad sometimes use stones, and international weight loss forums may reference stones when discussing UK participants.
3. Why is it called a stone?
Historical practice: Actual stones were used as standardized weights in medieval markets.
How it worked:
- A community selected a reference stone of agreed weight
- The stone was kept in the marketplace (sometimes literally built into a wall)
- Merchants used the reference stone on balance scales to verify weights
- Different stones existed for different commodities (wool stone, meat stone, etc.)
Modern name: The unit name "stone" is a fossil of this practice, long after actual stones stopped being used.
4. How do you convert stone to kilograms?
Formula:
Kilograms = Stone × 6.35029318
Quick approximation:
Kilograms ≈ Stone × 6.35 (good to 3 decimal places)
Examples:
- 10 stone × 6.35 = 63.5 kg
- 12 stone × 6.35 = 76.2 kg
- 15 stone × 6.35 = 95.25 kg
Online tools: Most conversion sites and apps include stone ↔ kilogram calculators.
5. How do British people talk about their weight?
Typical format: "I'm X stone Y pounds" or "I'm X stone Y"
Examples:
- "I'm 11 stone 7" = 11 stone + 7 pounds = 161 lb = 73 kg
- "I'm just over 12 stone" = slightly more than 168 lb
- "I'm nearly 10 stone" = approaching 140 lb
Rarely said:
- "I'm 11.5 stone" (uncommon—people say "11 stone 7" instead)
- "I'm 161 pounds" (too American—Brits don't think in pounds alone)
- "I'm 73 kilograms" (used by younger generations, but less common)
Conversational weight: Discussing weight is somewhat taboo, so people often avoid specifics: "I need to lose a bit of weight" rather than "I need to drop from 13 to 11 stone."
6. Do British bathroom scales show kilograms?
Yes, most modern scales show both.
Typical features:
- Default: Stones and pounds (st/lb)
- Toggle button: Switch to kilograms
- Dual display: Some show both simultaneously
Older scales: Analog scales from before 2000 often show stones only.
Buying scales in the UK: Even international brands (Fitbit, Garmin) sell UK-specific versions that default to stones.
7. Will the UK ever stop using stones?
Unlikely in the near future.
Reasons for persistence:
- Cultural attachment: Body weight is personal; people resist change
- Legal exemption: Personal weighing scales exempt from trade regulations
- NHS inertia: Changing medical records costly
- Generational use: Older generations use stones exclusively
- No enforcement: No push to mandate kilograms for personal use
Trend: Younger Brits (under 30) increasingly use kilograms, especially those who travel or use fitness apps with international audiences. However, the stone will likely persist for decades among older populations.
Comparison: Similar to Fahrenheit in the US—officially discouraged but culturally entrenched.
8. What is a "half stone"?
Half stone = 7 pounds = 3.175 kg
Usage:
- Weight loss: "I've lost half a stone" = 7 lb loss
- Weight gain: "I've put on half a stone over Christmas" = 7 lb gain
- Milestones: "Half-stone club" in weight loss programs
Why significant? Half a stone is a noticeable weight change—enough to affect how clothes fit and how you feel, but achievable in 3-7 weeks of dieting (at 1-2 lb/week loss).
9. How do you write stone and pounds?
Common formats:
Formal:
- "11 stone 7 pounds"
- "11 st 7 lb"
Informal:
- "11 stone 7"
- "11st 7lb" (no spaces)
- "11-7" (very casual, context-dependent)
Avoid:
- "11.7 stone" (ambiguous—could mean 11 stone 7 lb or 11 stone 9.8 lb)
- "11/7 st" (confusing notation)
Medical records: NHS typically uses "st/lb" format: "Patient weight: 12 st 3 lb"
10. Why do Americans not use stone?
The United States never adopted the stone for body weight.
Historical reasons:
- Colonial divergence: By the time the stone standardized in Britain (1824), the US had already established pounds as the body weight unit
- Decimal preference: Americans favored simpler base-10 systems where possible
- No cultural push: No equivalent to UK's Victorian-era adoption of stones for weighing people
Result: Americans think in pounds only:
- "I weigh 180 pounds" (no stones)
- Weight loss: "I lost 30 pounds" (not "2 stone 2 pounds")
Canadian note: Canada officially metricated in the 1970s and uses kilograms, not stones or pounds (though older Canadians may still think in pounds).
11. Is stone a legal unit?
Yes, in the UK and Ireland, but with restrictions.
Legal status:
- Personal use: Fully legal (bathroom scales, self-weighing)
- Trade: Must use metric (kilograms) for selling goods by weight
- Medical: Allowed in patient records (NHS uses stones)
Weights and Measures Act: Kilograms are the legal unit for commerce, but stones remain legal for "non-trade" purposes (personal weighing, medical records).
Comparison: Similar to miles on UK road signs—officially metric, but exceptions preserve traditional units in specific contexts.
12. How much is a stone in other historical weight units?
Stone in troy and apothecary systems:
Troy weight (precious metals):
- 1 stone (avoirdupois) = 14 pounds (avoirdupois)
- 1 pound (avoirdupois) = 7,000 grains
- 1 stone = 98,000 grains (troy)
- 1 troy pound = 5,760 grains
- 1 stone ≈ 17.01 troy pounds
Apothecaries' weight (pharmacy):
- Same grain as troy and avoirdupois (64.79891 mg)
- 1 stone = 98,000 grains (apothecaries')
Why this matters: Historically, pharmacists used apothecaries' weights, so understanding stone conversions was important for dosing medicines based on body weight.
About Ton (US) (ton)
How many pounds are in a US ton?
There are exactly 2,000 pounds (lb) in 1 US ton (short ton).
Quick conversion:
- 1 ton = 2,000 lb
- 0.5 ton = 1,000 lb
- 2 tons = 4,000 lb
- 10 tons = 20,000 lb
This is the defining relationship: the US ton is defined as exactly 2,000 avoirdupois pounds.
Is the US ton the same as the UK ton?
No. The US ton (short ton) is smaller than the traditional UK ton (long ton):
- US ton (short ton): 2,000 lb = 907.185 kg
- UK long ton: 2,240 lb = 1,016.047 kg
- Difference: The long ton is 240 lb (12%) heavier than the US ton
Modern UK usage: Today, the UK primarily uses metric tonnes (1,000 kg = 2,205 lb), not long tons. Long tons are historical and rarely used in modern commerce.
When it matters: Historical shipping documents, old engineering specifications, and traditional industries (coal mining, maritime) may reference long tons.
What is the difference between a ton and a tonne?
"Ton" (US short ton) and "tonne" (metric tonne) are different units:
US Ton (Short Ton):
- 2,000 pounds (exactly)
- 907.185 kilograms
- Used in United States
- Symbol: ton, st, US ton
Metric Tonne:
- 1,000 kilograms (exactly)
- 2,204.6 pounds
- Used internationally
- Symbol: t, tonne, MT
Key difference: The metric tonne is about 10% heavier (93 kg or 205 lb more) than the US ton.
Spelling note: "Tonne" (with "ne") specifically means metric tonne; "ton" can mean US short ton or UK long ton, requiring clarification.
How do you convert US tons to metric tonnes?
To convert US tons to metric tonnes, multiply by 0.907185 (or approximately 0.9):
Formula:
metric tonnes = US tons × 0.907185
Examples:
- 1 ton = 0.907 tonnes (just under 1 tonne)
- 10 tons = 9.07 tonnes (about 10% lighter)
- 100 tons = 90.7 tonnes
Reverse conversion (tonnes to tons):
US tons = metric tonnes × 1.102311
- 1 tonne ≈ 1.102 tons (about 10% heavier)
- 10 tonnes ≈ 11.02 tons
Practical approximation: For rough estimates, 1 ton ≈ 0.9 tonnes, or 1 tonne ≈ 1.1 tons.
Where is the US ton used?
The US ton (short ton) is primarily used in the United States for:
Industries and applications:
- Transportation: Trucking regulations, vehicle weight ratings (GVWR)
- Construction: Pricing gravel, sand, concrete, steel by the ton
- Waste management: Landfill fees, recycling tonnages
- Shipping: Domestic cargo weights, freight billing
- Agriculture: Crop yields, livestock feed, commodity trading
- Mining: Coal production, ore extraction
- Manufacturing: Steel, cement, paper production
International use: Almost all other countries use metric tonnes (1,000 kg) instead of US tons. The US is the only major economy still using short tons as the primary heavy-weight standard.
Trade caution: International shipping and trade contracts typically specify metric tonnes to avoid confusion between US tons, long tons, and metric tonnes.
What does "half-ton truck" mean?
"Half-ton truck" is a historical classification for light-duty pickup trucks, not a precise measurement of payload capacity.
Traditional meaning: Originally, "half-ton" meant the truck could carry approximately 1,000 lb (0.5 ton) payload.
Modern reality: Today's "half-ton" trucks (Class 2A) typically have payload capacities of 1,500-2,500 lb (0.75-1.25 tons)—often exceeding the historical "half-ton" rating.
Common "half-ton" models:
- Ford F-150
- Chevrolet Silverado 1500
- Ram 1500
- Toyota Tundra
- Nissan Titan
Other truck classifications:
- Half-ton (Class 2A): ~6,000-7,000 lb GVWR, ~1,500-2,000 lb payload
- Three-quarter-ton (Class 2B): ~8,500-10,000 lb GVWR, ~2,500-3,500 lb payload
- One-ton (Class 3): ~10,000-14,000 lb GVWR, ~3,000-4,500 lb payload
Important: Always check the vehicle's GVWR (Gross Vehicle Weight Rating) and payload capacity listed on the door jamb sticker or owner's manual, not the truck's name.
How much does a ton of gravel weigh?
This question seems circular, but it's asking about volume-to-weight relationship:
By definition: 1 ton of gravel = 2,000 pounds (that's what "ton" means)
But the real question is: How much volume (cubic yards)?
Volume equivalence:
- 1 ton of gravel ≈ 0.60-0.75 cubic yards (depending on gravel type and compaction)
- Loose gravel: 1 ton ≈ 0.75 cubic yards
- Compacted gravel: 1 ton ≈ 0.60 cubic yards
Reverse:
- 1 cubic yard of gravel ≈ 1.3-1.7 tons (2,600-3,400 lb depending on type)
Gravel types and density:
- Pea gravel: ~1.3 tons per cubic yard (lighter)
- Crushed stone: ~1.5 tons per cubic yard (typical)
- Dense granite: ~1.7 tons per cubic yard (heavier)
Practical example: If you need to cover a driveway area of 10 cubic yards, you'll need approximately 13-15 tons of gravel (10 yd³ × 1.3-1.5 tons/yd³).
What is the federal truck weight limit in tons?
The federal limit for trucks on interstate highways in the United States is:
80,000 pounds gross vehicle weight = 40 tons
This includes:
- Truck/tractor weight (tare weight)
- Trailer weight (tare weight)
- Cargo weight (payload)
- Fuel, driver, equipment
Axle limits:
- Single axle: 20,000 lb (10 tons) maximum
- Tandem axle: 34,000 lb (17 tons) maximum
- Total gross: 80,000 lb (40 tons) maximum
Bridge formula: The federal bridge formula determines allowable weight based on number of axles and spacing, which may further limit weight on shorter wheelbases.
State variations:
- Some states allow higher weights on specific routes (e.g., Michigan allows up to 164,000 lb / 82 tons with 11 axles)
- Permits: Overweight permits available for specialized hauling (heavy equipment, modular homes)
Violations: Fines for overweight trucks typically $0.10-$0.20 per pound over limit, escalating for serious violations.
How many tons can a dump truck carry?
Dump truck capacity varies by size and type:
Small dump trucks (single-axle):
- Payload: 5-8 tons (10,000-16,000 lb)
- Examples: Small commercial dumps, landscape trucks
- Typical load: 4-6 cubic yards material
Standard dump trucks (tandem-axle):
- Payload: 10-15 tons (20,000-30,000 lb)
- Examples: Construction dump trucks, municipal trucks
- Typical load: 8-12 cubic yards material
Tri-axle dump trucks:
- Payload: 15-18 tons (30,000-36,000 lb)
- Examples: Heavy construction, aggregate hauling
- Typical load: 12-15 cubic yards material
Transfer dump trucks (multi-axle):
- Payload: 20-26 tons (40,000-52,000 lb)
- Examples: Long combination vehicles, specialized hauling
- Typical load: 16-20 cubic yards material
Limitations:
- Federal limit: 80,000 lb (40 tons) gross vehicle weight
- Truck weight: Tare weight typically 15,000-30,000 lb (7.5-15 tons)
- Net payload: Actual cargo capacity = 40 tons minus truck weight
Material matters: Volume capacity depends on material density (sand ~1.5 tons/yd³, mulch ~0.4 tons/yd³).
What does "tonnage" mean in shipping?
In maritime shipping, "tonnage" can mean several different measurements:
1. Gross Tonnage (GT):
- Volume measurement of ship's entire internal space
- Not weight: Measured in "register tons" (100 cubic feet = 1 register ton)
- Usage: Ship classification, port fees, regulations
- Example: "Cargo ship: 50,000 GT"
2. Deadweight Tonnage (DWT):
- Weight measurement of cargo, fuel, crew, provisions ship can carry
- Actual weight capacity (what most people think of as "tonnage")
- Measured in: Metric tonnes (1,000 kg) internationally, sometimes US tons domestically
- Example: "Bulk carrier: 80,000 DWT" (can carry 80,000 tonnes cargo)
3. Displacement Tonnage:
- Total weight of ship (including ship structure + cargo + fuel + everything)
- Equals weight of water displaced by ship (Archimedes' principle)
- Usage: Naval vessels, ship design
- Example: "Aircraft carrier: 100,000 tons displacement"
4. Net Tonnage (NT):
- Volume of cargo spaces only (excludes engine room, crew quarters)
- Usage: Port fees, canal tolls (based on revenue-generating space)
Modern practice: International shipping primarily uses metric tonnes for weight measurements, while US domestic shipping may use US short tons.
Conversion Table: Stone to Ton (US)
| Stone (st) | Ton (US) (ton) |
|---|---|
| 0.5 | 0.004 |
| 1 | 0.007 |
| 1.5 | 0.011 |
| 2 | 0.014 |
| 5 | 0.035 |
| 10 | 0.07 |
| 25 | 0.175 |
| 50 | 0.35 |
| 100 | 0.7 |
| 250 | 1.75 |
| 500 | 3.5 |
| 1,000 | 7 |
People Also Ask
How do I convert Stone to Ton (US)?
To convert Stone to Ton (US), enter the value in Stone 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 Stone to Ton (US)?
The conversion factor depends on the specific relationship between Stone and Ton (US). 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 Ton (US) back to Stone?
Yes! You can easily convert Ton (US) back to Stone by using the swap button (⇌) in the calculator above, or by visiting our Ton (US) to Stone converter page. You can also explore other weight conversions on our category page.
Learn more →What are common uses for Stone and Ton (US)?
Stone and Ton (US) 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.
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Other Weight Units and Conversions
Explore other weight units and their conversion options:
- Kilogram (kg) • Stone to Kilogram
- Gram (g) • Stone to Gram
- Milligram (mg) • Stone to Milligram
- Pound (lb) • Stone to Pound
- Ounce (oz) • Stone to Ounce
- Ton (metric) (t) • Stone to Ton (metric)
- Ton (UK) (long ton) • Stone to Ton (UK)
- Microgram (µg) • Stone to Microgram
- Carat (ct) • Stone to Carat
- Slug (sl) • Stone to Slug
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