Ton Converter (metric, short & long tons)

Understanding the ton converter — concept and principle

The word "ton" means three different masses depending on where a document comes from. Most of the world, including Korea, uses the metric ton (tonne, t) of 1,000 kg. The United States uses the short ton of 2,000 pounds, and the United Kingdom traditionally used the long ton of 2,240 pounds. Use this converter for shipping weights, vehicle load limits, steel or grain prices quoted per ton, and trade statistics, so you never compare the wrong "ton".

How it is calculated

Every unit is expressed in metric tons, then the value is rescaled: result = value × t(from) ÷ t(to).

• 1 short ton = 2,000 lb = 907.18474 kg = 0.90718474 t
• 1 long ton = 2,240 lb = 1,016.0469088 kg ≈ 1.016046909 t
• 1 kg = 0.001 t; 1 lb = 0.45359237 kg exactly

The principle

All three tons are built on smaller units. The metric ton is simply 1,000 kilograms, so it fits the decimal SI system (it equals one megagram). The short and long tons are multiples of the avoirdupois pound, and since 1959 the international pound has been defined as exactly 0.45359237 kg. Multiplying 2,000 or 2,240 by that number gives exact kilogram values, so all conversions here are exact definitions rather than measurements. The long ton came from the British hundredweight of 112 lb (20 × 112 = 2,240), while the American hundredweight of 100 lb gives the 2,000 lb short ton.

Worked example

Default inputs: 1 metric ton to US short tons.

1. 1 t = 1,000 kg.
2. 1,000 kg ÷ 907.18474 kg = 1.102311311 short tons.
3. The same ton in long tons: 1,000 ÷ 1,016.0469088 = 0.9842065276.
4. In pounds: 1,000 ÷ 0.45359237 = 2,204.622622 lb.

How to read the result

The order is short ton < metric ton < long ton, but the gaps are small: about 10 % between short and metric, and only about 1.6 % between metric and long. That small gap is exactly why mistakes go unnoticed in invoices and freight quotes. If a US source says "ton" without a qualifier, it almost always means the short ton; in Korean and international trade, "톤" or "t" means the metric ton.

Common mistakes

• Assuming a US "ton" equals 1,000 kg; it is about 907 kg.
• Mixing up "ton" units of mass with ship "register tons" (a volume) or a "refrigeration ton" (a cooling power of 12,000 BTU/h).
• Rounding 1 t to 2,200 lb in large contracts, which loses about 4.6 lb per ton.

Frequently asked questions

Is a metric ton bigger than a US ton?

Yes. 1 metric ton is 1.1023 US short tons.

How many kilograms is a long ton?

Exactly 1,016.0469088 kg.

Is "tonne" the same as "metric ton"?

Yes. Both mean 1,000 kg; "tonne" is the spelling used in British English and in many standards.

Sources: NIST Special Publication 811 (2008), Guide for the Use of the SI, Appendix B · NIST Handbook 44, Appendix C — General Tables of Units of Measurement