Convert kilograms, grams, tonnes, pounds, ounces, stones and the Brazilian arroba in one table.
Eight units, one screen. The converter takes your value to kilograms — the SI base unit for mass — and from there produces milligrams, grams, kilograms, tonnes, ounces, pounds, stones and arrobas simultaneously. Seeing them together is the point: a recipe in ounces, a package in pounds and a scale in kilograms stop being three separate problems.
What makes this list different is the arroba. The name comes from the Arabic ar-rubʿ, "the quarter", and it reached Brazil with the Portuguese colonisers as roughly 14.7 kg, the weight of 32 arráteis. It was rounded to a clean 15 kg and never went away: cattle, coffee and cotton are still quoted in reais per arroba, and the boi gordo futures contract traded on B3 is priced that way. One catch worth knowing is that a live-cattle quote refers to the carcass, not the animal on its feet — the yield is typically 50% to 54% of live weight, so a 20-arroba steer is not a 300 kg animal.
The imperial units are exact by definition. Since 1959 the international pound is exactly 0.45359237 kg, the ounce is one sixteenth of that, and the British stone — still the everyday unit for body weight in the UK and Ireland — is fourteen pounds, about 6.35 kg. One honest caveat: strictly speaking these are units of mass, not weight. Weight is a force and changes with gravity, which is why a scale on the Moon would show a different number for the same kilogram. In everyday use the distinction rarely matters, and every conversion here runs entirely in your browser: nothing you type is sent to a server.
Every unit is converted through the kilogram: result = value × factor(source) ÷ factor(target). Exact factors: 1 mg = 0.000001 kg, 1 g = 0.001 kg, 1 t = 1000 kg, 1 lb = 0.45359237 kg, 1 oz = 1/16 lb = 0.028349523125 kg, 1 stone = 14 lb = 6.35029318 kg, 1 arroba (@) = 15 kg.
One arroba is 15 kg in Brazil. It is still the standard unit for pricing cattle, coffee and cotton, so 18 @ of live-cattle carcass is 270 kg.
Exactly 0.45359237 kg, which is about 454 g. Going the other way, 1 kg is roughly 2.2046 lb.
A stone is 14 pounds, or about 6.35 kg. It is mainly used in the UK and Ireland for body weight — "11 stone 4" means 11 × 6.35 kg plus 4 lb, around 71.7 kg.
Not strictly. Mass is how much matter something contains and is measured in kilograms; weight is the force gravity exerts on that mass and is measured in newtons. Bathroom scales report mass but everyone calls it weight, and this converter follows that everyday usage.
No. All the arithmetic happens in JavaScript on your device — nothing is uploaded or stored.
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