Unit Conversion

Convert numbers between two units quickly and precisely

Mass Converter

Unit Conversion

Convert mass units: kilograms, pounds, ounces, and stone

The mass converter converts between metric units (milligram, gram, kilogram, tonne) and the imperial/US system (pound, ounce, stone, short ton, long ton). It's useful for recipe conversions, lab work, shipping calculations, and international trade.

Key conversion factors:

  • 1 kilogram (kg) = 1,000 grams (g) – base unit of the metric system
  • 1 pound (lbs) = 453.59 grams – common unit of mass in the US and UK
  • 1 ounce (oz) = 28.35 grams – common for food and precious metals
  • 1 stone (st) = 6.35 kilograms – standard unit for body weight in the UK and Ireland
  • 1 short ton (us-t) = 907.18 kilograms – US ton
  • 1 long ton (uk-t) = 1,016.05 kilograms – British ton

Applications:

  • Cooking: converting imperial/US recipe amounts in pounds and ounces to grams
  • Body weight: comparing kilograms, stone, and pounds depending on the country
  • Logistics & shipping: calculating freight weights between metric and imperial units
  • Lab & chemistry: precise weighing of substances from milligrams to kilograms
  • Precious metals trading: converting ounce-based quotes (gold, silver) to grams

The mass converter delivers reliable values instantly – for international recipes, weight comparisons, or precise lab measurements. For the molar mass of a chemical compound, use the molar mass calculator, for density use the density converter.

Frequently asked questions about converting mass

1 pound (lbs, imperial) equals 453.59 grams. This differs from the colloquial German "Pfund", which traditionally means 500 grams – so it's worth checking the exact definition being used for international recipes or product labels.

The short ton (US ton) equals 907.18 kilograms, the long ton (British ton) 1,016.05 kilograms. Both differ from the metric tonne (1,000 kg), which is the most common internationally.

1 stone (st) equals 6.35 kilograms. Stone is mainly used in the UK and Ireland for body weight – a weight of, say, 11 stone equals about 69.9 kilograms.