Weight & Mass Converter

Convert mass accurately between milligrams, grams, kilograms, tonnes, ounces, pounds, stone, US tons, and long tons.

Convert instantly

Enter a value and choose the units. Your answer updates as you type.

Value

From

Result

0.001 Gram (g)

Quick reference

Milligram (mg)0.000001 base units
Gram (g)0.001 base units
Kilogram (kg)1 base units
Metric tonne (t)1000 base units
Avoirdupois ounce (oz)0.028349523125 base units
Avoirdupois pound (lb)0.45359237 base units
Stone (st)6.35029318 base units

About the Weight & Mass Converter

Mass and weight are often used interchangeably in everyday speech, but mass measures matter while weight is a force affected by gravity. This converter uses the international avoirdupois pound (exactly 0.45359237 kilograms), the metric tonne, the US short ton, and the Imperial long ton as distinct units so shipping and engineering calculations remain unambiguous.

Use the live result for recipes, laboratory work, shipping estimates, or personal measurements—for example, 5 pounds is approximately 2.26796185 kilograms. For force rather than mass, use the Force Converter; for an object's volume and density relationship, the Volume Converter is a useful companion.

Frequently asked questions

How many kilograms are in a pound?

One international avoirdupois pound equals exactly 0.45359237 kilograms.

What is the difference between a short and long ton?

A US short ton is 2,000 pounds; an Imperial long ton is 2,240 pounds. Neither is the same as a metric tonne.

Is a stone still used?

Yes. A stone equals 14 avoirdupois pounds, or exactly 6.35029318 kilograms, and remains common for body weight in the UK and Ireland.

Take this calculation further

Browse the converters calculators collection for more tools in this subject.

For a related calculation, use Mass Flow Converter to convert mass flow rate precisely between kg/s, kg/min, kg/h, g/s, pounds per hour, and tonnes per hour. Alternatively, use Volume Converter to convert volume between milliliters, liters, US and Imperial gallons, quarts, pints, cups, fluid ounces, and cubic units.

For the underlying method, read The Metric vs. Imperial System: A Practical Guide.