Ton (US) to Ton (metric) Converter

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).

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.

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