Short Ton vs Metric Tonne: What's the Difference?

The short answer

Two different definitions of "a ton"
Unit	Equals	In the other unit
US short ton	2,000 lb	907.18 kg
Metric tonne	1,000 kg	2204.62 lb

They are not the same weight: 1 short ton is 0.907 tonnes, and 1 tonne is 1.102 short tons. We've seen a quoted "ton" rating on an imported machine turn out to be a tonne — a 10% gap nobody caught until the number looked odd next to the crane chart. Mix them up on a rigging job and you understate the load by roughly a tenth.

Why there are two "tons"

The short ton (2,000 lb) is the ton used day to day in the US, built from 2,000 pounds because a US hundredweight is 100 lb. The metric tonne (1,000 kg) is simply one thousand kilograms, part of the metric system used almost everywhere else.

A third unit, the UK long ton, is 2,240 lb — heavier than a short ton again. It works out to about 1016.0 kg, or 1.016 tonnes. RigMaster does not use the long ton; it only reports US short tons or metric tonnes.

Which one does RigMaster show?

In the Load Weight Estimator, the Estimated Weight result gives Weight in whole pounds or kilograms, plus Tons or Tonnes, rounded to 2 decimals. Which label you see follows your unit setting: Tons (short tons of 2,000 lb) in Imperial, Tonnes (1,000 kg) in Metric — never both on the same screen.

Worked example: a copper round bar

Copper round bar, computed by RigMaster's Load Weight Estimator
Diameter × Length	Volume	Weight	Tons / Tonnes
1.5 ft × 8 ft (Imperial)	14.14 ft³	7,903 lb	3.95 ton
0.45 m × 2.4 m (Metric)	0.38 m³	3,418 kg	3.42 t

Same shape and material, sized separately in each unit system: 3.95 short tons in the imperial version, 3.42 tonnes in the metric one. Notice the tonne figure is the smaller number for a similar-sized bar — a tonne is the heavier unit, so it takes fewer of them to describe the same weight.

Converting a crane or sling rating

If a crane chart, sling tag or spec sheet gives a rating in tonnes and you are working in pounds (or the other way round), convert before you compare it with a RigMaster result in the wrong unit:

Short tons to tonnes: multiply by 0.907.
Tonnes to short tons: multiply by 1.102.
Or switch RigMaster's Units setting to match the rating on the chart or tag, and let the app do the rest of the calculation in that unit.

Common mistakes

Reading a metric tonne rating as a US ton, or the other way round, without converting — the gap is about 10%, enough to matter on a marginal pick.
Assuming "ton" always means 2,000 lb. A UK long ton (2,240 lb) and a metric tonne (2,205 lb) are both heavier than a short ton and close enough to each other to confuse.
Comparing a Tons figure from RigMaster directly against a tonne rating on equipment, or vice versa, without converting first.

Questions and answers

Is a ton the same as a tonne?

No. A US short ton is 2,000 lb (907.18 kg). A metric tonne is 1,000 kg (2204.62 lb), about 10.2% heavier.

How many pounds is a metric tonne?

2204.62 lb. A US short ton, by comparison, is exactly 2,000 lb.

Does RigMaster use short tons or metric tonnes?

Both, depending on your unit setting: the Load Weight Estimator shows Tons (short tons, 2,000 lb) in Imperial and Tonnes (1,000 kg) in Metric, never mixed on the same result.

What about the UK long ton?

A long ton is 2,240 lb, about 1016.0 kg — heavier than a US short ton and close to a metric tonne. RigMaster does not report it; only short tons and metric tonnes.

How to determine the weight of a load before lifting it · RigMaster

Short ton vs metric tonne: which one is heavier, and which one does RigMaster show?