Mass Converter

Convert mass between kilograms, grams, milligrams, micrograms, nanograms, picograms, femtograms, and attograms.

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 converts the same amount from kilograms down to attograms.

Use decimals or scientific notation.
UnitSymbolEquivalenceValue
kilogramkg1,000 g1e-6
gramg1 g0.001
milligrammg0.001 g1
microgramµg1e-6 g1000
nanogramng1e-9 g1e6
picogrampg1e-12 g1e9
femtogramfg1e-15 g1e12
attogramag1e-18 g1e15
Method: convert the input to the base unit first, then convert from that base unit to each target unit. The base unit is gram (g).

Mass conversions across practical and laboratory scales

This converter helps when reading protocols, preparing samples, comparing instrument outputs, or moving between kilogram, gram, milligram, microgram, and smaller SI scales.

Mass converter or weight converter?

Kilograms, grams, milligrams, and micrograms are mass units. In everyday language, people often search for a weight converter when they mean these mass conversions. For the physics distinction, see Mass vs. Weight: What's the Difference?.

Example

Enter 1 milligram to see that it equals 1,000 micrograms or 1e6 nanograms.