Short Tons to Long Tons Converter

What this converter does

It converts US short tons to imperial long tons — the two English-language tons, both built on the same avoirdupois pound and differing only in how many of them make a ton. Both are called ton in their home countries, and the 10.7 percent gap between them is neither a rounding error nor a matter of interpretation. This page exists so the two can never blur.

The formula

Multiply short tons by 0.892857142857 and onward, which is exactly the fraction 25 divided by 28. The decimal repeats forever; the fraction is exact, because 2,000 divided by 2,240 reduces cleanly. This tool computes with the exact ratio, so the repeating decimal is rendered to whatever precision you request without accumulating the error that a truncated constant would introduce.

Worked examples

One short ton is 0.8929 long tons. Twenty-eight short tons is exactly 25 long tons — the whole-number pair behind the ratio, and a useful checksum: any multiple of 28 short tons converts to a whole number of long tons. A hundred short tons is 89.29 long tons. A 2,000 short ton cargo is 1,785.71 long tons.

Why two tons exist at all

The divergence is entirely about the hundredweight. Britain kept the traditional hundredweight of 112 pounds — eight stone of fourteen pounds each — so twenty hundredweight made 2,240 lb. The United States rationalised the hundredweight to a decimal 100 pounds, so twenty made 2,000 lb. Both countries kept the words ton and hundredweight; only the brick underneath changed size. Every difference between American and British weight practice above the pound traces back to that single decision.

Where both tons meet

Transatlantic trade history, naval procurement, and metals and mining statistics that crossed the Atlantic for decades in both units. Modern documents mostly route around the problem by using the metric tonne, but archival and legal material keeps both alive, and reconciling an American series with a British one means applying this exact ratio rather than assuming the tons matched.

Which is closer to the tonne

The long ton, by a wide margin: 1.016 t against the short ton 0.907 t. That gives a quick diagnostic for an unlabelled ton figure sitting next to a metric one. If the two agree within about two percent, the ton was long; if the ton figure is roughly a tenth larger than the tonnes, it was short. The test is not a substitute for establishing the unit, but it is fast and usually decisive.

Precision and rounding

The ratio is exact as a fraction, so precision is limited only by display. The repeating decimal 0.892857 recurring is worth recognising on sight — its appearance in a spreadsheet constant is a reliable sign that someone converted short tons to long tons, and its truncation to 0.8929 introduces error in the fourth significant figure, which accumulates across a large series.

Common mistakes

Assuming the tons match, which is the error the page exists to prevent. Applying the ratio in the wrong direction, which turns a 10.7 percent reduction into a 12 percent increase. And converting through the tonne unnecessarily: the direct ratio is exact and simple, while a round trip through metric introduces two roundings where none is needed.

Benchmarks

1 short ton is 0.893 long tons. 5 is 4.464. 10 is 8.929. 25 is 22.321. 28 is exactly 25. 50 is 44.643. 100 is 89.286. 1,000 is 892.857. The 28-to-25 relationship is the one to remember, since it lets any conversion be checked by proportion without a calculator.

Accuracy and limits

Exact ratio, exact decimal arithmetic, display-only rounding, and a parser that refuses ambiguous input. Both units here are avoirdupois tons built on the 1959 pound; the metric tonne is a separate unit with its own pages, and this conversion deliberately does not pass through it.

The hundredweight underneath

Everything about this conversion traces to one decision. The US hundredweight is 100 pounds; the imperial hundredweight is 112. Twenty of each gives 2,000 and 2,240 respectively, and 100 over 112 reduces to the same 25 over 28 that governs the tons. Converting hundredweights between the systems uses the identical ratio, which is why the dedicated hundredweight page in this cluster and this one share their arithmetic exactly.

Reading a two-ton document

Documents that use both tons usually distinguish them as net and gross, where net is the short ton and gross the long. That vocabulary is a genuine hazard because gross and net normally mean with and without packaging, and a reader applying the ordinary sense will misinterpret the quantity by 12 percent while believing they have understood it. When both words appear near a ton figure in an American industrial document, they are probably naming the ton rather than describing the packaging.

Whole-number pairs

Because the ratio is 25 to 28, conversions land on whole numbers at every multiple of 28 short tons: 28 gives 25, 56 gives 50, 84 gives 75, 112 gives 100. That property makes proportional checking easy — a figure of 140 short tons must be 125 long tons exactly, and any converter disagreeing has a rounding problem. It is a small thing, and it makes verifying a conversion possible without any arithmetic at all.

What this conversion never touches

The metric system. Both units are avoirdupois tons resting on the same 1959 pound, so the conversion is a pure count ratio and never inherits the eight-digit metric constant. That is why it is exact as a fraction and why converting through tonnes would be strictly worse — two roundings introduced to reach an answer that one exact fraction already gives.

Neither is the metric tonne

It is worth stating plainly, because a page about two tons invites the assumption that they exhaust the options. They do not: the metric tonne of 1,000 kg is a third unit, larger than the short ton and smaller than the long ton, and it is what almost every modern document means. This conversion is for reading material where both English tons appear; anything current should be in tonnes, and the pages for that conversion are linked below.

Verifying a converted series

When converting a long run of figures, check a few against the 28-to-25 whole-number property rather than spot-checking arbitrary values. Any multiple of 28 short tons must give an exact whole number of long tons, so those rows verify instantly by eye. A converted series that fails that test somewhere has a rounding or a transcription problem at that point, and finding it by inspection is far quicker than recomputing everything.