How to convert weight
- 1.
Enter a mass
Type a number, e.g. 70 or 2.5.
- 2.
Pick units
Choose the source unit (e.g. kg) and the target unit (e.g. pound).
- 3.
Copy the result
The result updates live and can be copied in one click; the tables below show the same mass in every unit.
Key mass conversions
The pound is defined exactly as 0.45359237 kg, so every imperial mass unit converts to metric without rounding:
| Unit | Value | Notes |
|---|---|---|
| 1 milligram (mg) | 0.001 g | |
| 1 gram (g) | 0.001 kg | |
| 1 kilogram (kg) | 1000 g ≈ 2.2046 lb | SI base unit |
| 1 tonne (t) | 1000 kg | metric ton |
| 1 ounce (oz) | 28.349523125 g | = 1/16 lb |
| 1 pound (lb) | 453.59237 g | = 16 oz |
| 1 stone (st) | 6.35029318 kg | = 14 lb |
| 1 carat (ct) | 0.2 g | metric carat, gemstones |
Formulas: pounds = kg × 2.20462, kg = pounds × 0.453592, grams = ounces × 28.3495.
Kilograms to pounds and back
Example: 70 kg × 2.20462 = 154.32 lb. The other way: 180 lb × 0.45359237 = 81.65 kg.
| Kilograms | Pounds | Pounds | Kilograms |
|---|---|---|---|
| 1 kg | 2.2046 lb | 1 lb | 0.4536 kg |
| 5 kg | 11.023 lb | 10 lb | 4.5359 kg |
| 10 kg | 22.046 lb | 50 lb | 22.680 kg |
| 50 kg | 110.23 lb | 100 lb | 45.359 kg |
| 70 kg | 154.32 lb | 150 lb | 68.039 kg |
| 100 kg | 220.46 lb | 200 lb | 90.718 kg |
Body weight in stones and pounds
In the UK and Ireland body weight is usually given as stones and pounds, e.g. "11 st 4 lb". Formula: kg = (stones × 14 + pounds) × 0.45359237. So 11 st 4 lb = 158 lb = 71.67 kg.
| Stones and pounds | Total pounds | Kilograms |
|---|---|---|
| 9 st 0 lb | 126 lb | 57.15 kg |
| 10 st 0 lb | 140 lb | 63.50 kg |
| 11 st 4 lb | 158 lb | 71.67 kg |
| 12 st 8 lb | 176 lb | 79.83 kg |
| 14 st 0 lb | 196 lb | 88.90 kg |
Once you have your weight in kilograms, you can check it with the BMI calculator.
Common mistakes
- Decimal stones. 11.4 st is not 11 st 4 lb - it is 11 st 5.6 lb, because a stone has 14 pounds, not 10.
- Weight ounces vs fluid ounces. An ounce (28.35 g) measures mass; a fluid ounce (29.57 ml US) measures volume. They only match for water-like liquids.
- Troy ounces. Gold and silver are priced per troy ounce (31.1035 g), which this converter does not use.
- Short and long tons. The US ton is 907.2 kg and the UK long ton 1016 kg; the converter uses the metric tonne (1000 kg).
Frequently asked questions
How many grams are in an ounce?
+
1 ounce = 28.3495 g (exactly 28.349523125 g). A troy ounce used for precious metals is 31.1035 g.
How many pounds are in a kilogram?
+
1 kg = 2.20462 lb. Quick estimate: kilograms × 2.2.
How many pounds are in a stone?
+
1 stone = 14 pounds = 6.35 kg.
What is 70 kg in stones?
+
70 kg = 154.32 lb = 11 st 0.3 lb, i.e. just over 11 stone.
How many grams are in a carat?
+
A metric carat is exactly 0.2 g (200 mg). It is unrelated to the karat that describes gold purity.
What is a decagram?
+
1 decagram (dag) = 10 g - a unit still used on Polish shop counters, where "10 dag" of cheese means 100 g.
Updated: