Weight conversions come up constantly for the same handful of reasons: a recipe or parcel listed in pounds and ounces needs a metric equivalent, a UK bathroom scale reads in stone, or a US shipping form wants pounds where the rest of the world would use kilograms. Stone is the odd one out — used routinely for body weight in the UK and Ireland but almost nowhere else, and easy to get wrong because it is a unit of 14 pounds rather than a round metric-style number.
Calculators in this section
The calculators below cover the pairs people actually need: kilograms to pounds, pounds to stone, ounces to grams and the reverse of each, alongside the less common tonne and US-ton conversions that trip people up because a metric tonne (1,000 kg) and a US short ton (2,000 lb, about 907 kg) are not the same unit despite the similar name.