lbs to kg converter
This lbs to kg converter turns pounds into kilograms as you type, for a body weight read on an American bathroom scale, a weight printed on a label or a form that only takes metric.
Formula: kg = lb × 0.45359237 100 × 0.45359237 = 45.359237
In every unit (28)
- Nanogram4.5359 × 10¹³ ng
- Microgram45,359,237,000 µg
- Milligram45,359,237 mg
- Gram45,359.237 g
- Decagram4,535.9237 dag
- Kilogram45.359237 kg
- Megagram0.04535924 Mg
- Quintal0.45359237 q
- Tonne0.04535924 t
- Short ton0.05 Short t
- Long ton0.04464286 Long t
- Short hundredweight1 Short cwt
- Long hundredweight0.89285714 Long cwt
- Stone7.14285714 st
- Stone + Pound7 st 2 lb
- Quarter3.57142857 qtr
- Ounce1,600 oz
- Pound + Ounce100 lb 0 oz
- Dram25,600 dr
- Grain700,000 Gr
- Troy Pound121.52777778 Troy lb
- Troy Ounce1,458.33333333 Troy Oz
- Troy Pound + Ounce121 Troy lb 6.3 Troy Oz
- Troy grain700,000 Troy gr
- Newton444.82216153 N
- Kilonewton0.44482216 kN
- Carat226,796.185 ct
- Catty90.718474 Jin
Using the lbs to kg converter: one exact factor
Enter a weight in pounds and the kilograms appear at once, with grams, ounces and stones in the list underneath. The page opens on 100 lb, which is 45.36 kg. Decimals and sums work as typed: 3×12.5 adds up three 12.5 lb bags and gives 17.01 kg in one go.
Since 1959, the international avoirdupois pound has been fixed at exactly 0.45359237 kilogram, the factor NIST lists. Converting pounds to kg means multiplying by that number. The lbs to kg converter keeps all eight decimals, so 180 lb comes to 81.65 kg rather than a rounded guess.
No calculator at hand? Halve the pounds, then take away a tenth of the result: 220 lb gives 110, minus 11, so about 99 kg. The trick runs a little under, by less than one percent, so use the lbs to kg converter for any figure that goes on a form.
Common values
| lb | kg |
|---|---|
| 1 | 0.4536 |
| 2 | 0.9072 |
| 5 | 2.268 |
| 8 | 3.6287 |
| 10 | 4.5359 |
| 15 | 6.8039 |
| 20 | 9.0718 |
| 25 | 11.3398 |
| 30 | 13.6078 |
| 40 | 18.1437 |
| 50 | 22.6796 |
| 70 | 31.7515 |
| 100 | 45.3592 |
| 150 | 68.0389 |
| 180 | 81.6466 |
| 200 | 90.7185 |
Body weight, labels and luggage in pounds
Bathroom scales sold in the US read in pounds, while a doctor abroad or a fitness app set to metric wants kilograms. A reading of 150 lb is 68.04 kg, and 200 lb is 90.72 kg. The kilograms also feed the BMI formula, which divides the weight in kilograms by the height in meters squared. For a UK form that asks for stones, the lbs to stone converter splits the same reading the British way.
Many medicines for children are dosed per kilogram of body weight, so a weight has to go from pounds to kilograms before anyone does the math. Take the exact figure from the lbs to kg converter and leave the dose itself to a doctor or a pharmacist.
Birth weights in the US are usually announced in pounds and ounces, while hospitals in metric countries write grams. For a birth weight such as 7 lb 8 oz, pick Pound + Ounce as the starting unit: the lbs to kg converter returns 3.4 kg, or 3,402 g.
A food label works the same way. A 5 lb bag of flour holds 2.27 kg, handy when a European recipe lists its flour in grams. A suitcase weighed at home on a luggage scale in pounds still has to meet a limit often set in kilograms: our baggage allowance by airline guide gives both units. For the other direction, from kilograms to pounds, use the kg to lbs converter.