Tonnage Glossary: Metric, Short & Long Ton, DWT, DMT

Short Ton (US Ton)

The standard unit of weight measurement used in the United States, equal to 2,000 pounds (907.185 kilograms). This is the most common tonnage unit in American commerce, construction, and freight industries.

Common Usage Predominantly used in the United States for commercial goods, construction materials, and domestic freight.

Equivalent 2,000 lbs = 907.185 kg = 0.907 metric tons

Metric Ton (Tonne)

The international standard unit of mass equal to 1,000 kilograms (2,204.62 pounds). Abbreviated as 't' or 'MT', this is the most widely used tonnage measurement in global trade and shipping.

Common Usage International shipping, scientific applications, and most countries outside the United States.

Equivalent 1,000 kg = 2,204.62 lbs = 1.102 short tons

Long Ton (Imperial Ton)

A unit of weight equal to 2,240 pounds (1,016.05 kilograms), historically used in the British Imperial system. Still occasionally encountered in some Commonwealth countries and in certain commodity markets.

Common Usage Historical British measurements, some petroleum and mineral commodities.

Equivalent 2,240 lbs = 1,016.05 kg = 1.12 short tons

Net Ton (Net Register Tonnage)

A measure of the usable cargo-carrying capacity of a ship, calculated as the total internal volume minus spaces not available for cargo (engine rooms, crew quarters, etc.). Used primarily in port fees and canal toll calculations. Note: in US weight usage, "net ton" is also a synonym for the 2,000 lb short ton, so check the context.

Common Usage Maritime shipping, port authority fees, canal transit charges.

Equivalent 1 net ton = 100 cubic feet of cargo space

Gross Ton (Gross Register Tonnage)

A measure of a ship's total internal volume, including all enclosed spaces. Calculated as 100 cubic feet per gross ton. Used for regulatory purposes, safety requirements, and crew certifications.

Common Usage Ship registration, maritime regulations, safety manning requirements.

Equivalent 1 gross ton = 100 cubic feet of total internal volume

Deadweight Tonnage (DWT)

The total weight a vessel can safely carry, including cargo, fuel, freshwater, ballast water, provisions, passengers, and crew. It represents the difference between a ship's displacement when fully loaded versus when empty.

Common Usage Bulk carrier and tanker capacity ratings, charter agreements, freight calculations.

Equivalent Expressed in metric tons or long tons depending on region

Displacement Tonnage

The actual weight of a vessel measured by the weight of water it displaces. Used primarily for naval vessels and is the truest measure of a ship's actual mass.

Common Usage Naval architecture, warship specifications, shipbuilding.

Equivalent Typically expressed in long tons (naval) or metric tons

Tipping Fee

The charge levied by a landfill, transfer station, or waste processing facility to accept waste material, typically calculated per ton. Also known as a gate fee or disposal fee.

Common Usage Waste management, demolition projects, municipal services, recycling economics.

Equivalent Ranges from $25-$150+ per ton depending on location and waste type

Payload Capacity

The maximum weight of cargo a vehicle, vessel, or aircraft can safely transport. Calculated by subtracting the vehicle's curb weight (empty weight) from its gross vehicle weight rating (GVWR).

Common Usage Trucking, logistics planning, fleet management, load optimization.

Equivalent Standard semi-trailer: ~44,000 lbs (22 short tons)

Ton-Mile

A unit of freight measurement representing the transport of one ton of cargo over one mile. Used to compare transportation efficiency and calculate freight costs across different modes.

Common Usage Freight rate calculation, transportation efficiency metrics, logistics analysis.

Equivalent 1 ton-mile = moving 1 ton of cargo 1 mile

Revenue Ton (Freight Ton)

The basis on which ocean freight is charged—either by weight (1 metric ton) or volume (1 cubic meter), whichever yields greater revenue. Ships use this to optimize cargo revenue.

Common Usage Ocean freight pricing, container shipping, break-bulk cargo.

Equivalent 1 revenue ton = 1 metric ton OR 1 cubic meter (whichever is greater)

Measurement Ton (Freight Measurement)

A unit of volume used in ocean shipping equal to 40 cubic feet (1.133 cubic meters). Used when cargo is measured by volume rather than weight, common for light, bulky goods.

Common Usage Ocean freight for low-density cargo, shipping rate calculations.

Equivalent 40 cubic feet = 1.133 cubic meters

Cubic Ton

A volume measurement used in timber and shipping industries, typically equal to 40 cubic feet. Not to be confused with weight-based tonnage measurements.

Common Usage Timber industry, shipbuilding lumber, some shipping applications.

Equivalent 40 cubic feet = approximately 1.133 cubic meters

Assay Ton

A specialized unit used in precious metals assaying, equal to 29.167 grams. This precise weight is chosen so that the number of milligrams of precious metal recovered equals the number of troy ounces per short ton of ore.

Common Usage Mining assays, precious metals testing, ore grade determination.

Equivalent 29.167 grams; results in mg = troy oz/short ton

Register Ton

A unit of ship volume equal to 100 cubic feet (2.83 cubic meters), used in the calculation of gross and net register tonnage. It measures enclosed space rather than weight.

Common Usage Ship registration, port dues, Panama/Suez Canal tolls.

Equivalent 100 cubic feet = 2.83 cubic meters

Cost Per Ton-Hour

A metric used in mining and heavy industry to measure the cost of moving material, calculated by dividing total operating costs by tons moved per hour. Critical for equipment efficiency analysis.

Common Usage Mining operations, quarry management, heavy equipment economics.

Equivalent Total hourly cost ÷ tons moved per hour

Dry Metric Ton (DMT)

A metric ton of material measured after its moisture content has been subtracted. Iron ore, concentrates, wood chips and biomass are often priced per dry metric ton so buyers don't pay for water.

Common Usage Iron ore, mineral concentrates, pulp, biomass and wood-chip contracts.

Equivalent DMT = wet metric tons × (1 − moisture %)

Wet Metric Ton (WMT)

A metric ton of material as weighed, including its natural moisture. Shipping weights and freight are usually based on wet tons, while the commodity itself may be priced on a dry basis.

Common Usage Bulk shipping, ore and concentrate trade, biomass logistics.

Equivalent Price per WMT = price per DMT × (1 − moisture %)

Hundredweight (cwt)

A unit of mass used for pricing livestock, grain, LTL freight and some metals. The US hundredweight is 100 lb; the UK (long) hundredweight is 112 lb. Twenty hundredweights make one ton in either system.

Common Usage US LTL freight rates, cattle and grain markets, UK historical trade.

Equivalent US: 100 lb = 45.36 kg (1/20 short ton); UK: 112 lb = 50.80 kg

Quintal

A unit of mass equal to 100 kilograms, widely used for agricultural produce in India, Latin America and parts of Europe and Africa (sometimes spelled "kwintal"). Ten quintals make one metric ton.

Common Usage Grain, cotton, sugarcane and vegetable prices in India, Brazil, Mexico and elsewhere.

Equivalent 1 quintal = 100 kg = 0.1 metric ton = 220.46 lb

W/M (Weight or Measurement)

An ocean freight billing rule where cargo is charged per metric ton or per cubic meter, whichever gives the larger number of freight tons. A shipment of 3 t occupying 5 m³ is billed as 5 revenue tons.

Common Usage LCL ocean freight, break-bulk cargo, project cargo quotes.

Equivalent Chargeable tons = max(metric tons, cubic meters)

Tonne-Kilometre (tkm)

The metric counterpart of the ton-mile: one metric ton of cargo moved one kilometre. Used to express freight rates and transport emissions.

Common Usage European and international freight rates, carbon accounting, transport statistics.

Equivalent 1 tonne-km ≈ 0.685 short ton-miles

Dry Short Ton (DST)

A short ton (2,000 lb) of material measured on a moisture-free basis. Common in North American pulp, biosolids and wood-fibre pricing.

Common Usage US pulp and paper, biosolids, biomass fuel contracts.

Equivalent 1 DST = 0.9072 dry metric tons

Quick Tonnage Conversions

Weight conversion factors between tonnage units. To convert prices, use the price per ton converter.

From	To	Multiply By
Short tons	Metric tons	0.9072
Metric tons	Short tons	1.1023
Short tons	Long tons	0.8929
Long tons	Short tons	1.1200
Long tons	Metric tons	1.0160
Metric tons	Long tons	0.9842
Short tons	Pounds (lbs)	2,000
Metric tons	Kilograms (kg)	1,000
Metric tons	Quintals	10
Short tons	Hundredweight (cwt)	20

Common Questions

What is the difference between a metric ton and a short ton?

A metric ton (tonne) equals 1,000 kg or about 2,204.62 lb. A short ton, used in the United States, equals 2,000 lb or about 907.185 kg. The metric ton is roughly 10% heavier, so confusing the two creates a 10% pricing error.

What is deadweight tonnage (DWT)?

Deadweight tonnage is the total weight a ship can carry: cargo, fuel, fresh water, ballast, crew and provisions. It is the standard capacity measure for bulk carriers and tankers. A Panamax bulk carrier is typically 65,000–80,000 DWT.

What is a tipping fee?

A tipping fee (gate fee) is the per-ton charge to dispose of waste at a landfill, transfer station or processing facility. In the US it ranges from about $30 to more than $150 per ton depending on location and waste type.

What does net ton vs gross ton mean for ships?

Gross tonnage measures a ship's total enclosed volume; net tonnage measures only the cargo spaces. Both are volume measures, not weights, and are used for port fees, canal tolls and regulation.

What does a $400 per metric ton premium mean?

A premium is an amount added on top of a benchmark price. A $400/t premium on a metal priced at $2,800/t on the exchange means you pay $3,200 per metric ton, usually to cover location, form, quality or delivery terms.