How to convert weights
- Enter the value.
- Pick the unit you have under From and the unit you need under To.
- Read the result at the top. Below it you will find the exact factor, the reverse factor and a table with the same weight in every unit.
How it works
Every unit is stored as an exact number of kilograms. The pound is the anchor for the imperial units: since 1959, 1 lb is exactly 0.45359237 kg, an ounce is a sixteenth of that and a stone is fourteen pounds.
| Unit | Exact size in kilograms |
|---|---|
| milligram | 0.000001 |
| gram | 0.001 |
| ounce | 0.028349523125 |
| pound | 0.45359237 |
| stone | 6.35029318 |
| metric ton | 1,000 |
To convert, the tool multiplies by the size of the “from” unit and divides by the size of the “to” unit, so there is no rounding until the number is shown.
Worked example
Convert a 12 stone 4 pound body weight to kilograms.
- Convert to pounds: 12 × 14 + 4 = 172 lb.
- Convert pounds to kilograms: 172 × 0.45359237 = 78.02 kg.
- Or use stone directly: 12.2857 st × 6.35029318 = 78.02 kg.
Enter 172 with From set to pounds and To set to kilograms to see it.
Useful weight facts
- A kilogram is 1,000 grams and about 2.2 pounds.
- A carat is 200 milligrams, so gem weights convert with the milligram unit.
- Recipes in cups are less precise than grams. If you can weigh, do.
- Postal and airline limits are usually written in kilograms, so convert your luggage before you leave.
Popular pairs
For quick answers, use kg to lbs or stones to kg, each with a table of common values. Switch to the length converter for sizes, or the temperature converter for oven settings.
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