Weight Converter
Convert between kilograms, pounds, ounces, grams, stones, metric tons, and US tons instantly.
Quick Reference
How to Convert Weight Units
Weight (more precisely, mass) conversion works by converting the input to a base unit (kilograms), then to the target unit. This converter handles both metric and imperial weight units.
Common Conversion Factors
| From | To | Multiply by |
|---|---|---|
| Kilograms | Pounds | 2.20462 |
| Pounds | Kilograms | 0.453592 |
| Ounces | Grams | 28.3495 |
| Grams | Ounces | 0.035274 |
| Stones | Kilograms | 6.35029 |
| Metric Tons | Kilograms | 1,000 |
| US Tons | Kilograms | 907.185 |
Weight vs Mass
In everyday use, "weight" and "mass" are used interchangeably. Scientifically, mass is the amount of matter in an object (measured in kilograms), while weight is the force exerted by gravity on that mass (measured in newtons). On Earth's surface, a 1 kg mass weighs approximately 9.81 newtons.
Body Weight Quick Reference
| Kilograms | Pounds | Stones & Lbs |
|---|---|---|
| 50 kg | 110.2 lbs | 7 st 12 lbs |
| 60 kg | 132.3 lbs | 9 st 6 lbs |
| 70 kg | 154.3 lbs | 11 st 0 lbs |
| 80 kg | 176.4 lbs | 12 st 8 lbs |
| 90 kg | 198.4 lbs | 14 st 2 lbs |
| 100 kg | 220.5 lbs | 15 st 10 lbs |
Mass vs weight — and why most "weight" converters convert mass
Strictly, mass (kilograms, grams, pounds, ounces) is the amount of matter in an object. Weight is the gravitational force on that mass (newtons, pound-force). In everyday English we use "weight" to mean mass, and almost every "weight converter" — including this one — converts between mass units. On the Moon you would have one-sixth the weight but the same mass. For Earth-bound use the distinction rarely matters; for physics homework and aerospace calculations it always does.
Common conversions
| From | To | Factor |
|---|---|---|
| 1 kilogram (kg) | pounds (lb) | 2.20462 |
| 1 pound (lb) | grams | 453.592 |
| 1 ounce (oz, avoirdupois) | grams | 28.3495 |
| 1 stone (UK) | kilograms | 6.35029 |
| 1 stone | pounds | 14 |
| 1 metric ton (tonne, t) | kilograms | 1,000 |
| 1 short ton (US) | kilograms | 907.185 |
| 1 long ton (UK) | kilograms | 1,016.05 |
| 1 troy ounce (precious metals) | grams | 31.1035 |
| 1 carat (gemstones) | grams | 0.2 |
Why "ounce" is dangerous without context
- Avoirdupois ounce — the everyday ounce. 28.35 g. Used for food, postal weights, body weight.
- Troy ounce — used exclusively for precious metals (gold, silver, platinum). 31.10 g. A "1 oz gold coin" weighs 31.1 g, not 28.35 g.
- Fluid ounce — a volume, not a mass. US fl oz = 29.57 mL; UK fl oz = 28.41 mL. Recipes routinely conflate "8 oz of butter" (mass) with "8 oz of water" (volume) — they happen to be similar for water at room temperature but radically different for flour, sugar, or chocolate.
Conversions to memorise
- 1 kg ≈ 2.2 lb. A 75 kg adult weighs ~165 lb.
- 1 lb ≈ 454 g. Half a kilo is roughly 1.1 lb.
- 1 stone = 14 lb. 12 st 7 lb = 175 lb = 79.4 kg.
- 1 oz ≈ 28 g (avoirdupois). A 4 oz portion of meat ≈ 113 g.
- 1 tonne ≠ 1 short ton ≠ 1 long ton. Always specify if it matters.