Weight Converter
Convert between kilograms, pounds, ounces, grams, stones and tons in both directions with a table of every result.
Weight Converter — input your values
What does this conversion calculator do?
The weight converter translates any mass between metric, imperial and avoirdupois units — from milligrams up to long tons. It covers everyday units like kilograms, pounds, ounces and grams as well as stones and the different ton variants.
Every unit is converted through the kilogram as a fixed reference, so conversions are identical in both directions and always use the exact international definitions of each unit.
Formula and variables
1 lb = 0.45359237 kg exactly; 1 oz = 28.349523125 g exactly; a stone is 14 lb.
| Symbol | Meaning |
|---|---|
| factor(from) | How many kilograms one 'from' unit equals |
| factor(to) | How many kilograms one 'to' unit equals |
Worked example
Convert 5 pounds into kilograms.
- 1 lb = 0.45359237 kg, so 5 lb = 5 × 0.45359237 = 2.26796 kg.
Answer: 5 lb ≈ 2.27 kg.
Tips and common mistakes
Tips
- For rough mental math: 1 kg ≈ 2.2 lb, and 1 lb ≈ 0.45 kg.
- A stone is exactly 14 lb — divide pounds by 14 to get stones.
- Remember that grams and milligrams are metric: there are 1,000 g in a kg and 1,000 mg in a g.
- Use the conversion table to find handy reference pairs like kg→lb (×2.2046) or oz→g (×28.35).
Common mistakes to avoid
- Confusing the short ton (2,000 lb, used in the US) with the long ton (2,240 lb, used in the UK) or the metric tonne (1,000 kg).
- Mixing up fluid ounces (volume) with ounces (weight) in recipes.
- Rounding the pound conversion too early — 1 lb is exactly 0.45359237 kg, not 0.45.
Weight Converter — frequently asked questions
How many pounds are in a kilogram?
One kilogram equals approximately 2.20462 pounds. So 10 kg ≈ 22.05 lb.
How do I convert ounces to grams?
Multiply ounces by 28.349523125. For example, 8 oz × 28.35 ≈ 226.8 g.
What is a stone in kilograms?
One stone is exactly 14 pounds, which equals 6.35029318 kg. It is still commonly used for body weight in the UK and Ireland.
What's the difference between a ton and a tonne?
A metric tonne is 1,000 kg. A US short ton is 2,000 lb (907.18 kg) and a UK long ton is 2,240 lb (1,016.05 kg).
Is weight the same as mass?
Not quite — mass is the amount of matter, while weight is the force of gravity on it. On Earth the difference is negligible for everyday conversions, so the units are used interchangeably.
How many grams are in an ounce?
One avoirdupois ounce is exactly 28.349523125 g. So 1 oz ≈ 28.35 g, a common shortcut in cooking.