Mass / Weight Converter (kg, g, lb, oz…)
Convert mass between milligrams, grams, kilograms, tonnes, ounces, pounds, stone, and US tons — one value into every unit, with a reference table.
Mass conversion reference
| 1 unit | g | kg | oz | lb |
|---|---|---|---|---|
| 1 mg | 0.001 | 0.000001 | 0.000035274 | 0.00000220462 |
| 1 g | 1 | 0.001 | 0.035274 | 0.00220462 |
| 1 kg | 1 000 | 1 | 35.274 | 2.20462 |
| 1 t | 1 000 000 | 1 000 | 35 274 | 2 204.62 |
| 1 oz | 28.3495 | 0.0283495 | 1 | 0.0625 |
| 1 lb | 453.592 | 0.453592 | 16 | 1 |
| 1 st | 6 350.29 | 6.35029 | 224 | 14 |
| 1 ton | 907 185 | 907.185 | 32 000 | 2 000 |
Converting mass units
Like length, mass is measured in a metric family (gram, kilogram, tonne) and an imperial / US family (ounce, pound, stone, ton). They meet at a single exact definition: one pound is 0.453 592 37 kilograms. Enter a value and its unit to see it in every unit at once.
The relationships worth remembering
Metric steps by factors of a thousand: 1000 mg in a gram, 1000 g in a kilogram, 1000 kg in a tonne. In the imperial system there are 16 ounces in a pound and 14 pounds in a stone, while a US (short) ton is 2000 pounds. The handy cross-over figure is that one kilogram is about 2.205 pounds.
Worked example
A 70 kg person weighs 70 × 2.2046 ≈ 154.3 pounds, which is 154.3 / 14 ≈ 11.02 stone. A 12 oz packet is 12 × 28.35 ≈ 340.2 grams. The conversions are exact ratios, so what you get back is precise.
Mass or weight?
Strictly, these units measure mass — the amount of matter — while weight is the force gravity exerts on it. In everyday use the two are used interchangeably on Earth, which is why this is often called a weight converter; the numbers are the same for any practical purpose here.
Mass, weight, and which ton
A kilogram is a mass; a pound is used for both a mass and a force depending on context. On Earth the distinction rarely bites, which is why it catches people out when it does — for a calculation involving forces, establish which you have first. The other ambiguity is the ton: a US short ton is 2,000 lb, a UK long ton 2,240 lb, and a metric tonne 1,000 kg. All three are called "ton" in ordinary speech and they differ by up to 12%.