Is a metric ton the same as a tonne?

Yes. 'Metric ton' and 'tonne' are the same unit: exactly 1,000 kg. 'Metric ton' is common in the US where 'tonne' might be unfamiliar; 'tonne' is the official SI-adjacent term used internationally.

What does 'ton' mean in the US vs UK?

In the US, an unqualified 'ton' almost always means a short ton (2,000 lb). In the UK, an unqualified 'ton' historically meant a long ton (2,240 lb), but modern UK usage increasingly means metric tonne (1,000 kg). Always qualify.

What is a 'gross ton' in shipping?

In maritime shipping, 'gross tonnage' (GT) is a dimensionless measure of a ship's internal volume, not its weight. 1 gross tonnage = 100 cubic feet (2.832 m³) of enclosed volume. It is unrelated to the mass units discussed here.

How many kg is a short ton?

1 short ton = 2,000 lb × 0.453592 kg/lb = 907.185 kg.

Tonne vs Ton: Metric Ton, Short Ton, and Long Ton Explained

Three different units are all called 'ton' in everyday speech, yet they differ by up to 12%. In shipping, agriculture, mining, and international trade, using the wrong 'ton' can mean significant discrepancies. This guide explains each variant, gives exact conversion factors, and tells you which is used where.

Published March 19, 2026

Key takeaways

Metric tonne (t): 1,000 kg = 2,204.62 lb. The SI standard; used internationally in trade and science.
US short ton (ton): 2,000 lb = 907.185 kg. Standard in the US for freight, agriculture, and mining.
Imperial long ton (long ton): 2,240 lb = 1,016.05 kg. Historical British unit; still used in some UK shipping contexts.
The metric tonne is 10% heavier than a short ton and 1.6% lighter than a long ton.
Avoid unqualified 'ton' in international contracts — always specify metric, short, or long.

The metric tonne

The metric tonne (symbol: t) is defined as exactly 1,000 kilograms. It is the large-mass unit used by the International System of Units (SI) and is the standard for international commodity trade, shipping manifests, and scientific data.

Note the spelling: tonne (with an 'e') denotes the metric unit specifically, while 'ton' alone is ambiguous. 1 tonne = 1,000 kg = 2,204.623 lb. In many countries, 'tonne' and 'metric ton' are used interchangeably.

The US short ton

The short ton is the standard 'ton' in the United States. It equals exactly 2,000 pounds avoirdupois, which is 907.18474 kg — about 10% less than a metric tonne.

The short ton is used across US agriculture (grain yields reported in short tons per acre), mining (coal production), and freight (truck payload ratings). When a US news article says 'tons of steel,' it almost certainly means short tons.

The imperial long ton

The long ton (also called the 'gross ton' in some shipping contexts) is the traditional British imperial unit. It equals 2,240 pounds = 20 hundredweight (cwt), where 1 hundredweight = 112 lb.

2,240 lb = 1,016.0469 kg — slightly heavier than a metric tonne. The long ton was the standard for the British coal and shipping industries. The UK officially adopted the metric tonne in 1965, but long tons persist in some maritime and historical contexts.

Conversion table

Formula

1 metric tonne = 1,000 kg = 2,204.62 lb = 1.10231 short tons = 0.984207 long tons
1 short ton     = 907.185 kg = 2,000 lb = 0.907185 metric tonnes = 0.892857 long tons
1 long ton      = 1,016.05 kg = 2,240 lb = 1.01605 metric tonnes = 1.12 short tons

Which ton does your industry use?

International shipping and trade: metric tonne. Incoterms and most international contracts default to metric tonnes.

US freight, agriculture, mining: short ton. USDA crop reports, EPA emissions inventories, and US mining statistics all use short tons.

UK maritime and some industrial contexts: long ton still appears in older documentation. Modern UK trade uses metric tonnes.

Aviation: kilograms or metric tonnes. MTOW (maximum take-off weight) is in kg or tonnes.

Oil industry: sometimes 'metric ton of oil equivalent' (toe) — a unit of energy, not mass.

Ambiguity in international contracts

Important

The difference between a short ton and a metric tonne is ~10%. On a 10,000-unit commodity contract, this is a significant discrepancy. Many trade disputes have arisen from assuming 'ton' means one thing when a counterparty assumed another.

Best practice: always specify 'metric tonne (t)', 'short ton (US)', or 'long ton (UK)' in contracts, shipping documents, and technical specifications. Never use the bare word 'ton' where precision matters.

Common practical examples

Steel production: global steel output is reported in metric tonnes. China produced approximately 1,000 million metric tonnes of steel in a recent year. When US sources convert this to 'tons,' they may mean short tons (1,000 Mt = ~1,102 million short tons).

Coal: the US Energy Information Administration (EIA) reports coal production in short tons. Other countries report in metric tonnes. A US 'ton' of coal weighs 907 kg; a metric 'tonne' of coal weighs 1,000 kg.

Shipping containers: a standard 20-foot container (TEU) has a maximum payload of about 28 metric tonnes. This limit is specified in metric tonnes in almost all international shipping documents.

Agriculture: grain prices on the Chicago Board of Trade (CBOT) are quoted in US dollars per short ton or bushel. International grain trade is quoted in metric tonnes. Traders must convert carefully — 1 metric tonne of wheat ≠ 1 short ton of wheat.

In all these cases, the 10% difference between metric and short tons is large enough to matter in pricing, logistics, and regulatory reporting. When in doubt, use metric tonnes and label them clearly.