Pounds, kilograms, ounces and stone
Since the 1959 international yard and pound agreement the pound is defined as exactly 0.45359237 kg (NIST SP 811), so every conversion below is exact; only the display is rounded.
- lb and oz: US body weight, groceries and shipping. 1 lb = 16 oz; 1 oz = 28.349523125 g.
- kg and g: the SI units, used on nutrition labels, medicine doses and almost everywhere outside the US.
- stone (st): body weight in the UK and Ireland. 1 st = 14 lb = 6.350293 kg.
- Tons: a US (short) ton is 2,000 lb = 907.185 kg, a UK (long) ton is 2,240 lb = 1,016.047 kg, and a metric ton (tonne) is 1,000 kg.
- Arroba: 15 kg, the unit of Brazil's cattle market (prices per @ of carcass).
1 lb = 0.45359237 kg (exact) 1 kg = 2.204623 lb
1 oz = 28.349523125 g 1 g = 0.035274 oz
1 st = 14 lb = 6.350293 kg 1 US ton = 907.18474 kg
Pounds to kg and stone table
| lb | kg | st |
|---|---|---|
| 1 lb | 0.45359 | 0.071429 |
| 5 lb | 2.268 | 0.35714 |
| 10 lb | 4.5359 | 0.71429 |
| 25 lb | 11.34 | 1.7857 |
| 50 lb | 22.68 | 3.5714 |
| 100 lb | 45.359 | 7.1429 |
| 120 lb | 54.431 | 8.5714 |
| 150 lb | 68.039 | 10.714 |
| 165 lb | 74.843 | 11.786 |
| 180 lb | 81.647 | 12.857 |
| 200 lb | 90.718 | 14.286 |
| 250 lb | 113.4 | 17.857 |
| 300 lb | 136.08 | 21.429 |
Worked example
A body weight of 165 lb: 165 × 0.45359237 = 74.84 kg. In stone: 165 ÷ 14 = 11.79, i.e. 11 st 11 lb. In the kitchen, 8 oz of butter is 8 × 28.3495 = 226.8 g.
Frequently asked questions
How many kg is 1 lb?
1 lb = 0.453592 kg (exactly 0.45359237 kg by definition). Going the other way, 1 kg = 2.20462 lb.
How do I convert kg to lbs quickly?
Multiply by 2.2 for a quick estimate (exact: 2.20462). 70 kg ≈ 154 lb.
How many pounds is a stone?
1 stone = 14 lb = 6.35 kg. 12 st is 168 lb, or 76.2 kg.