This weight converter moves between kilograms, pounds, ounces, stones and grams instantly — edit any field and all the others follow. Built for body weight, luggage, parcels and recipes alike.
Type in any box. Anchors: 1 kg = 2.20462 lb exactly as the world defines it; 1 stone = 14 lb (the British body-weight unit); 16 ounces make a pound. Pair the result with the BMI Calculator when the weight is a person’s.
The Conversion Factors
- 1 pound = 0.45359237 kg — exact by international treaty since 1959 (the only weight factor with legal force, and the one this converter is built on)
- 1 kg = 2.20462 lb | 1 oz = 28.3495 g | 1 stone = 6.35029 kg = 14 lb
- Mental math: kg → lb, double it and add a tenth (70 kg → 140 + 14 = 154 lb ✔). lb → kg, halve it and subtract a tenth (154 → 77 − 7.7 = 69.3 ≈ 69.85 ✔)
This converter is part of our Conversion Calculators collection.
Reference Weights
| Thing | kg | lb |
|---|---|---|
| Checked airline bag limit (typical) | 23 | 50 |
| Newborn baby (average) | 3.4 | 7.5 |
| Bag of sugar (UK) | 1 | 2.2 |
| Olympic barbell (men’s) | 20 | 44 |
| Adult (global average) | 62 | 137 |
| Adult, 70 kg reference person | 70 | 154.3 |
| Compact car (approx.) | 1,100 | 2,425 |
Weight vs. Mass (the Pedant’s Corner, Briefly)
Strictly, kilograms measure mass and pounds here are pounds-force at Earth’s gravity — but on Earth’s surface they convert by the constant above, and scales do the worrying for you. On the Moon the same 70 kg person would “weigh” 11.6 kg by a spring scale (bathroom scales measure force), yet their mass — and what matters for BMI — stays 70 kg. Also beware: troy ounces (31.1 g, for precious metals) are not the avoirdupois ounces (28.35 g) used here for everyday weight.
Related Tools
- BMI Calculator — put the converted weight to work
- Conversion Calculators — the full collection
Frequently Asked Questions
How many pounds are in a kilogram?
2.20462. So 70 kg = 154.32 lb, and 100 kg = 220.46 lb. Multiply kilograms by 2.20462 (or double-and-add-a-tenth for a close mental answer).
How many kilograms is 154 pounds?
69.85 kg — the reverse of the example above (pounds × 0.45359237).
What is a stone in weight?
A British unit equal to exactly 14 pounds (6.35 kg). An 11-stone person weighs 154 lb / 70 kg — body weight in the UK and Ireland is conventionally quoted in stone and pounds.
How many ounces in a kilogram?
35.274 oz. And a pound is 16 oz — the imperial system’s base-16 quirk next to metric’s clean multiples of 10 and 1000.
Why does my weight show differently on kg and lb scales?
Usually rounding and calibration rather than conversion error — plus genuine daily fluctuation of 1–2 kg from water and meals, which swamps any factor question. Weigh at the same time of day for consistency.
Is this weight converter free?
Yes — free, instant, no sign-up, live conversion as you type.