The short ton is a unit of mass equal to 2,000 pounds (907.18474 kg).[1] In the United States it is often called simply ton[1] without distinguishing it from the metric ton (tonne, 1,000 kilograms / 2,204.62262 pounds) or the long ton (2,240 pounds / 1,016.0469088 kilograms); rather, the other two are specifically noted. There are, however, some U.S. applications for which unspecified tons normally means long tons (for example, Navy ships)[2] or metric tons (world grain production figures).
Both the long and short ton are defined as 20 hundredweights, but a hundredweight is 100 pounds (45.359237 kg) in the U.S. system (short or net hundredweight) and 112 pounds (50.80234544 kg) in the Imperial system (long or gross hundredweight).[1]
A short ton–force is 2,000 pounds-force (8,896.443230521 N).
Prior to metrication, Canada followed the US practice in using the word "ton" to refer to the short ton, and "hundredweight" to mean the short hundredweight. Since metrication, the generic term 'ton' may cause confusion when used verbally as to whether the speaker means the short ton or the tonne (metric ton).
In the UK, short tons are rarely used. The word "ton" is taken to refer to a long ton, and metric tons are distinguished by using the alternative "tonne" spelling.