Weight converter online
Convert between 12 units of mass instantly: kilograms, pounds, ounces, grams, tonnes, stones, carats and more. No sign-up, no ads.
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Weight conversion table
Quick reference conversions between the most common units.
| Source weight | Kilograms (kg) | Grams (g) | Pounds (lb) | Ounces (oz) |
|---|---|---|---|---|
| 100 g | 0.1 | 100 | 0.22046 | 3.52740 |
| 500 g | 0.5 | 500 | 1.10231 | 17.6370 |
| 1 kg | 1 | 1,000 | 2.20462 | 35.2740 |
| 5 kg | 5 | 5,000 | 11.0231 | 176.370 |
| 10 kg | 10 | 10,000 | 22.0462 | 352.740 |
| 1 stone | 6.35029 | 6,350.29 | 14 | 224 |
| 1 metric tonne | 1,000 | 1,000,000 | 2,204.62 | 35,273.96 |
Metric and imperial systems: a practical guide
The metric system (SI) is the scientific and industrial standard used across most of the world. Its main units of mass are the gram (g), kilogram (kg, the SI base unit) and metric tonne (t = 1,000 kg). Smaller units such as the milligram (mg) and microgram (μg) are essential in pharmacology, chemistry and nutrition labelling.
The imperial system, used in the US and partially in the UK, uses the ounce (oz), pound (lb = 16 oz) and short ton (2,000 lb). The UK also retains the stone (st = 14 lb) for body weight and the long ton (2,240 lb) in industrial contexts. The US short ton is 907 kg; the UK long ton is 1,016 kg.
In jewellery and gemology, the metric carat (ct) is the international standard for weighing gemstones: 1 ct = exactly 0.2 g. Do not confuse it with the karat (kt), which measures the proportion of pure gold in an alloy (24 kt = pure gold).
Frequently asked questions about weight conversion
How many kilograms are in a pound?
One pound (lb) equals exactly 0.453592 kg. Conversely, 1 kg = 2.204623 lb. The pound is the everyday mass unit in the US and UK.
How do you convert kilograms to ounces?
Multiply kilograms by 35.2740. Example: 2 kg × 35.2740 = 70.548 oz. One ounce is 28.3495 grams.
What is a stone in weight?
The stone (st) is used mainly in the UK and Ireland for body weight. 1 st = 14 lb = 6.35029 kg. A person weighing 70 kg is approximately 11 stone.
What is the difference between a metric tonne, short ton and long ton?
The metric tonne (t) = 1,000 kg (SI). The US short ton = 907.185 kg (2,000 lb). The UK long ton = 1,016.047 kg (2,240 lb).
What is a carat as a unit of weight?
The metric carat (ct) measures the mass of gems and diamonds: 1 ct = exactly 0.2 g = 200 mg. Don't confuse it with the karat (kt), which measures gold purity in an alloy.