Weight & Mass Converter
Convert between different units of weight and mass including kilograms, pounds, ounces, grams, stones, and more.
Weight & Mass Conversion Calculator
Common Weight Conversions
Weight & Mass Units Reference
Metric System
- 1 t = 1,000 kg
- 1 kg = 1,000 g
- 1 g = 1,000 mg
- 1 ct = 200 mg
Imperial System
- 1 ton (US) = 2,000 lb
- 1 ton (UK) = 2,240 lb
- 1 st = 14 lb
- 1 lb = 16 oz
Key Conversions
- 1 kg = 2.205 lb
- 1 oz = 28.35 g
- 1 st = 6.35 kg
- 1 gr = 64.8 mg
Understanding Weight & Mass Conversions
In everyday use "weight" and "mass" are treated as the same thing, and this converter follows that convention, working between grams, kilograms, metric tonnes, ounces, pounds, stones and US tons. Internally each unit is referenced to the kilogram, the SI base unit of mass.
The key fixed relationship is that 1 pound equals exactly 0.45359237 kilograms, from which everything else follows: 16 ounces to a pound, 14 pounds to a stone (a unit still common in the UK and Ireland for body weight). Be careful with "tons", a US (short) ton is 2,000 pounds, while a metric tonne is 1,000 kg, so they are not interchangeable.
Frequently Asked Questions
How many pounds are in a kilogram?
One kilogram equals approximately 2.20462 pounds. To convert kilograms to pounds, multiply by 2.20462.
How many grams are in an ounce?
One ounce equals approximately 28.3495 grams.
What is the difference between a ton and a tonne?
A metric tonne is 1,000 kilograms (about 2,204.6 lb), while a US short ton is 2,000 pounds (about 907.2 kg).
How many pounds are in a stone?
One stone equals exactly 14 pounds, a unit still widely used for body weight in the UK and Ireland.