Weight & Mass Converter
Convert between kilograms, pounds, ounces, grams, stones, tonnes, and more weight units.
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How to use this calculator
- 1
Enter the weight value you want to convert in the "From" field.
- 2
Select your starting unit (e.g. kilograms) from the first dropdown.
- 3
Select the target unit (e.g. pounds) from the second dropdown.
- 4
The converted result appears immediately. Use the swap button to reverse.
Frequently asked questions
How many pounds are in a kilogram?
One kilogram equals approximately 2.20462 pounds. To convert kg to lbs, multiply by 2.20462.
How many grams are in an ounce?
One ounce equals approximately 28.3495 grams. To convert ounces to grams, multiply by 28.3495.
What is a stone in kilograms?
One stone equals 6.35029 kilograms or 14 pounds. Stone is primarily used in the UK and Ireland for measuring body weight.
What is the difference between mass and weight?
Mass is the amount of matter in an object (measured in kilograms) and does not change with gravity. Weight is the gravitational force on that mass (measured in newtons) and varies by location. In everyday use, the two terms are used interchangeably.
How many kilograms in a metric ton?
A metric ton (tonne) is exactly 1,000 kilograms. It should not be confused with a US short ton (907.185 kg) or a UK long ton (1,016.05 kg).
Weight and mass conversion explained
How to use the weight & mass
Use this weight & mass to onvert between kilograms, pounds, ounces, grams, stones, tonnes, and more weight units. Enter your values above and get your result in seconds. The tool is free, works on all devices, and keeps your data private — nothing is stored or shared.
How the weight & mass works
The weight & mass converter uses standard formulas used in unit conversion in science, engineering, cooking, and everyday use. Enter your inputs, and the tool calculates the result instantly in your browser. No server-side processing means your data stays on your device. Results update in real time as you change inputs.
Metric vs imperial weight
The metric system uses grams and kilograms as its primary weight units. The imperial system, used in the US, uses ounces and pounds. The UK also uses stones for body weight. The exact conversion is: 1 pound = 0.45359237 kilograms (an international standard since 1959).
Key weight conversion factors
1 kg = 2.20462 lb | 1 lb = 453.592 g | 1 oz = 28.3495 g | 1 stone = 6.35029 kg = 14 lb | 1 metric ton = 1,000 kg | 1 US short ton = 907.185 kg | 1 UK long ton = 1,016.05 kg.
Practical uses for weight conversion
Weight conversions are needed in cooking and baking (recipes in grams vs cups/ounces), shipping and freight (packages in kg vs lbs), medicine and pharmacy (drug dosages), international trade, and fitness (body weight in kg vs lbs vs stones).
Weight & mass: how it works
Unit conversion matters across engineering, science, cooking, and everyday life. This tool applies internationally recognised conversion factors to deliver precise, instant results across all major unit systems — no manual lookup needed.
Who uses this tool?
Scientists, engineers, chefs, and international travellers use this tool daily to bridge the gap between different measurement systems. It eliminates the need to memorise conversion factors or hunt through reference tables.
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Results are estimates for informational purposes only and do not constitute professional financial, medical, legal, or technical advice. Read full disclaimer →