Weight and Mass Converter
Convert mass between metric and imperial units for cooking, shipping, fitness and science.
Result
Enter a value to convert.
How to use this calculator
- Enter a value and pick the from and to units.
- Swap units with the arrow button.
- All other units are listed below the main result.
Formula
Every unit is converted through kilograms using exact definitions:
- 1 pound (lb) = 0.45359237 kg
- 1 ounce (oz) = 1/16 lb = 28.349523125 g
- 1 metric tonne = 1,000 kg
result = value × (kg per from-unit) ÷ (kg per to-unit)
Worked example
150 pounds in kilograms
150 × 0.45359237 = 68.0388555 kg.
500 grams in ounces
0.5 kg ÷ 0.028349523125 = 17.63698097 oz.
Assumptions and limitations
- Ounces and pounds are avoirdupois units, used for everyday goods. Troy ounces (used for precious metals) are different.
- Fluid ounces measure volume, not weight; use the Volume Converter.
- “Weight” here means mass, as it does in everyday use.
Frequently asked questions
How many pounds are in a kilogram?
About 2.20462 pounds, because one pound is exactly 0.45359237 kg.
Is a metric tonne the same as a US ton?
No. A metric tonne is 1,000 kg. A US (short) ton is 2,000 lb, about 907 kg, and a UK (long) ton is 2,240 lb, about 1,016 kg.