Complete guide: Weight and Mass
Updated:
This everyday weight converter converts mass, not force. One kilogram equals 1,000 grams and one metric tonne 1,000 kilograms. Short and long tons are not used to avoid confusing them with metric tonnes.
An avoirdupois pound is exactly 0.45359237 kg and contains 16 avoirdupois ounces. A stone is 14 pounds. Troy ounces for precious metals and fluid ounces, which measure volume, are not included.
Equivalences use internal precision and display up to ten significant digits. Very small quantities use scientific notation so they do not appear to be zero. Changing units does not change the object or replace a real measurement.
Sources and conversion conventions
Document review: 2026-10-24
How it works
- 1Select units or the applicable reference.
- 2Enter the quantity or size you want to compare.
- 3Check the breakdown and equivalence conventions.
Frequently asked questions
Can different physical quantities be converted?
No. Each converter keeps one physical quantity. Converting mass to volume requires the substance's density.
Can I share a conversion with its values?
Yes. The link retains quantity, units and all entered options; recipients can reproduce the result and edit the inputs.