Weight Converter
Convert between metric and imperial weight units — mg, g, kg, tonnes, ounces, pounds and stone.
This calculator provides estimates only, for general information and entertainment purposes. It isn't professional advice — confirm anything important independently before relying on it.
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How this calculator works
This converter covers the weight and mass units people search for most: milligrams, grams, kilograms and metric tonnes on the metric side; ounces, pounds and stone on the imperial side.
All conversions go through grams as a common base. The international pound has been defined as exactly 453.59237 grams since 1959, so pound-based conversions (ounces, pounds, stone) are exact, not approximate.
Worked example: to convert 70 kilograms to pounds, 70kg × 1000 = 70,000g, then 70,000 ÷ 453.59237 ≈ 154.32 lb. Going the other way, a 10-pound bag of flour is 10 × 453.59237 ≈ 4,536g, or about 4.5kg.
A few reference points are handy to keep in mind: a standard letter-sized bag of sugar is 1kg (≈2.2lb), an average adult male in Australia weighs roughly 85kg (≈13.4 stone), and a newborn baby is typically 3–4kg (≈6.6–8.8lb). Postal and freight weights are usually quoted in kilograms and grams in Australia, while some gym equipment, recipe books and body-weight figures — especially from the UK and US — still use pounds or stone, which is where this converter is most useful.
A common mixup is confusing mass (kilograms, pounds) with weight-as-force, or assuming "ounces" always means the same thing — a fluid ounce (a volume measurement) is a completely different unit from the ounce of mass used here, and the two aren't interchangeable even though they share a name.
Frequently asked questions
- How many pounds are in a kilogram?
- 1 kilogram is approximately 2.20462 pounds (1000g ÷ 453.59237g per pound).
- How many pounds are in a stone?
- 1 stone is exactly 14 pounds — a unit still commonly used for body weight in the UK and Ireland.
- Is an ounce of weight the same as a fluid ounce?
- No — this calculator converts ounces of mass/weight (1oz ≈ 28.35g). A fluid ounce measures volume, not weight, and the two units aren't directly convertible without knowing the density of what you're measuring.
- How many grams are in a tonne?
- 1 metric tonne is 1,000,000 grams (1,000kg) — used for large quantities like freight, produce yields, or vehicle weights, rather than the imperial "ton" (2,000lb), which is a different, slightly smaller unit.