What is a stone?
A stone is 14 pounds, or about 6.35 kilograms, and the United Kingdom and Ireland use it almost entirely for body weight. Elsewhere people use kilograms or pounds.
We provide a calculator on this site to convert stones to kilograms.
What is a metric ton (or tonne)?
A metric ton, or tonne (t), is 1,000 kilograms, which is about 2,204.62 pounds. Most countries use it for cargo and bulk goods such as grain and ore.
The metric ton (1,000kg) is about 10% heavier than the US short ton of 2,000 pounds and about 1.6% lighter than the UK long ton of 2,240 pounds. Spelling it 'tonne' is the usual way to avoid the confusion.