Popular weight conversions
Weight & mass units
Mass is the amount of matter in an object; in everyday speech it is called weight. The SI base unit is the kilogram, defined since 2019 through the Planck constant. The international avoirdupois pound is defined as exactly 0.45359237 kilograms.
| Unit | Symbol | In kilograms | Definition |
|---|---|---|---|
| Microgram | µg | 1 × 10⁻⁹ kg | One millionth of a gram, common on supplement labels as mcg. |
| Milligram | mg | 0.000001 kg | One thousandth of a gram. |
| Gram | g | 0.001 kg | One thousandth of a kilogram. |
| Kilogram | kg | 1 kg | The SI base unit of mass, defined through the Planck constant. About 2.20462 pounds. |
| Tonne | t | 1,000 kg | A metric ton: exactly 1,000 kilograms. |
| Quintal | q | 100 kg | One hundred kilograms, widely used for crops and produce in India and parts of Europe. |
| Carat | ct | 0.0002 kg | Exactly 200 milligrams, used for gemstones. Not the same as the karat purity scale for gold. |
| Tola | tola | 0.0116638038 kg | A traditional South Asian unit of 180 grains, about 11.66 grams, still used for gold and silver. |
| Grain | gr | 0.00006479891 kg | Exactly 64.79891 milligrams; 7,000 grains make a pound. |
| Ounce | oz | 0.02834952313 kg | An avoirdupois ounce: exactly 28.349523125 grams, or 1/16 of a pound. |
| Troy ounce | ozt | 0.0311034768 kg | Exactly 31.1034768 grams, the standard unit for precious metals. |
| Pound | lb | 0.45359237 kg | The avoirdupois pound: exactly 0.45359237 kilograms, or 16 ounces. |
| Stone | st | 6.35029318 kg | Fourteen pounds, about 6.35 kilograms, commonly used for body weight in the UK and Ireland. |
| US ton | ton | 907.18474 kg | The US short ton: exactly 2,000 pounds. |
| Imperial ton | LT | 1,016.046909 kg | The imperial long ton: exactly 2,240 pounds. |
Calculate with weight
The smart calculator does arithmetic across weight units and picks a sensible unit for the answer. Try 2 lb 4 oz + 300 g to kg.
Questions and answers
Which weight units can I convert?
All 15: micrograms, milligrams, grams, kilograms, tonnes, quintals, carats, tolas, grains, ounces, troy ounces, pounds, stone, US tons, imperial tons.
What is the SI unit of weight?
This converter uses the kilogram (kg) as its base unit. Mass is the amount of matter in an object; in everyday speech it is called weight. The SI base unit is the kilogram, defined since 2019 through the Planck constant. The international avoirdupois pound is defined as exactly 0.45359237 kilograms.
What is the difference between a ton and a tonne?
A tonne (metric ton) is 1,000 kg. A US short ton is 2,000 lb (907.18 kg) and an imperial long ton is 2,240 lb (1,016.05 kg).
How precise are the results?
Factors are the exact legal definitions where one exists (an inch is exactly 2.54 cm, a pound exactly 0.45359237 kg). Results show 10 significant digits by default; the precision menu offers 4 to 15.
Does the weight converter work offline?
Yes. ConvertEasy is a progressive web app: after your first visit it keeps working with no connection, and you can install it to your home screen from the browser menu.