How to use it
- Type the amount in the Value field.
- Choose the unit you have under From and the one you need under To; Swap units reverses the direction.
- Read the headline result with the exact factor both ways. When the target is pounds, ounces or stone, the panel also gives the “lb oz” and “st lb” readings.
- The table below shows the same mass in all twelve units; copy the result, the table or the link.
Example
70 kg in pounds: 70 ÷ 0.45359237 = 154.323584 lb, which is 154 lb 5.2 oz or 11 st 0.3 lb. The other way, 8 oz of flour is 8 × 28.349523125 = 226.8 g, and a 1-carat diamond weighs exactly 0.2 g.
Formula and unit factors
Each unit is stored as its mass in kilograms; a conversion multiplies by the source factor and divides by the target factor:
value in TO = value in FROM × (kg per FROM) ÷ (kg per TO)
70 kg → lb: 70 × 1 ÷ 0.45359237 = 154.323584| Unit | Symbol | Kilograms |
|---|---|---|
| Milligram | mg | 0.000001 |
| Gram | g | 0.001 |
| Kilogram | kg | 1 |
| Tonne (metric ton) | t | 1,000 |
| Ounce | oz | 0.028349523 |
| Pound | lb | 0.45359237 |
| Stone | st | 6.3502932 |
| US ton (short) | US ton | 907.18474 |
| UK ton (long) | UK ton | 1,016.0469 |
| Grain | gr | 0.00006479891 |
| Troy ounce | oz t | 0.031103477 |
| Carat | ct | 0.0002 |
The avoirdupois pound has been exactly 0.45359237 kg since the 1959 international yard and pound agreement; the ounce (1/16 lb), stone (14 lb), grain (1/7,000 lb), short ton (2,000 lb) and long ton (2,240 lb) follow from it. The troy ounce is 480 grains (31.1034768 g) and is used for precious metals only; the metric carat has been 200 mg since 1907. Fluid ounces are a volume and are not covered here.
Sources: NIST SP 811 – Guide for the Use of the International System of Units, Appendix B, NIST Handbook 44, Appendix C – General Tables of Units of Measurement.
Questions
- How do I convert kg to lbs?
- Multiply kilograms by 2.20462 (or divide by 0.45359237). 70 kg is 154.3 lb; 100 kg is 220.5 lb. For pounds to kilograms, multiply by 0.4536.
- How many grams are in an ounce?
- One avoirdupois ounce is 28.3495 g, so 100 g is 3.53 oz. A troy ounce, used for gold and silver, is heavier at 31.1035 g.
- What is a stone in kg?
- One stone is 14 lb or 6.35 kg. Body weight in the UK is often given in stone and pounds: 12 st 6 lb is 174 lb or 78.9 kg.
- What is the difference between a ton and a tonne?
- A metric tonne is 1,000 kg (2,204.6 lb). A US short ton is 2,000 lb (907.2 kg) and a UK long ton is 2,240 lb (1,016 kg). The converter lists all three separately.