Mass Converter

Convert units of mass commonly used for weight, including kilograms, grams, pounds, ounces, stones, tonnes, US and UK tons, and laboratory metric units.

This calculator is useful when you need a quick unit check without working through each conversion factor by hand. Enter one value to compare every supported unit side by side.

Mass Converter

Enter a mass and choose its starting unit. The table lists metric and laboratory units first, followed by US and UK mass units.

Use decimals or scientific notation.
UnitSymbolConversion factor1 g =
metric tonnet1 t = 1 × 106 g1 × 10−6t
kilogramkg1 kg = 1,000 g0.001kg
gramg1 g = 1 g1g
milligrammg1 mg = 0.001 g1,000mg
microgramµg (mcg)1 µg = 1 × 10−6 g1 × 106µg
nanogramng1 ng = 1 × 10−9 g1 × 109ng
picogrampg1 pg = 1 × 10−12 g1 × 1012pg
femtogramfg1 fg = 1 × 10−15 g1 × 1015fg
attogramag1 ag = 1 × 10−18 g1 × 1018ag
ounceoz1 oz = 28.349523 g0.035273962oz
poundlb1 lb = 453.59237 g0.0022046226lb
stonest1 st = 6,350.2932 g0.00015747304st
US short tonUS ton1 US ton = 907,184.74 g1.1023113 × 10−6US ton
UK long tonUK ton1 UK ton = 1.0160469 × 106 g9.8420653 × 10−7UK ton
Method: the entered mass is converted to grams first, then from grams to each listed unit.

Everyday and laboratory mass conversions

This converter includes everyday units such as pounds, ounces, stones, kilograms, and grams, along with milligrams, micrograms, nanograms, and other laboratory-scale metric units.

Compare all supported units

Enter a value and choose its starting unit to calculate the equivalent amount in every supported mass unit. The conversion table lets you compare metric, US customary, imperial, and laboratory units at the same time.

Mass converter or weight converter?

The kilograms, grams, pounds, ounces, and other units used by this calculator are treated as units of mass. In everyday language, these measurements are also commonly described as weight. For a more detailed explanation of the scientific distinction, read Mass vs. Weight: What's the Difference?.

Mass conversion examples

  • 1 pound equals 16 ounces or 453.59237 grams.
  • 1 kilogram equals 1,000 grams or approximately 2.20462 pounds.
  • 1 milligram equals 1,000 micrograms or 1,000,000 nanograms.