Lbs to Kg Converter — Pounds to Kilograms, Exact

How to convert pounds to kilograms

Multiply the pounds by 0.45359237:

kilograms = pounds × 0.45359237

150 lb × 0.45359237 = 68.0388555 kg, or 68.04 kg rounded to two decimals. Going the other way, divide by the same number: 68.04 kg ÷ 0.45359237 = 150 lb. The kg to lbs converter does that direction with its own table.

The converter rounds to two decimals but keeps at least four significant digits, so small weights don’t turn into zeros: 0.3 lb is 0.1361 kg, not 0.14. Choose Decimal places for a fixed number of decimals, or read the Exact line under the result.

Pounds to kilograms table

Pounds (lb)	Kilograms (kg)
1 lb	0.4536 kg
2 lb	0.9072 kg
3 lb	1.361 kg
4 lb	1.814 kg
5 lb	2.268 kg
6 lb	2.722 kg
7 lb	3.175 kg
8 lb	3.629 kg
9 lb	4.082 kg
10 lb	4.536 kg
15 lb	6.804 kg
20 lb	9.072 kg
25 lb	11.34 kg
30 lb	13.61 kg
40 lb	18.14 kg
50 lb	22.68 kg

Body weight, from 100 to 300 pounds:

Pounds (lb)	Kilograms (kg)
100 lb	45.36 kg
110 lb	49.9 kg
120 lb	54.43 kg
130 lb	58.97 kg
140 lb	63.5 kg
150 lb	68.04 kg
160 lb	72.57 kg
170 lb	77.11 kg
180 lb	81.65 kg
190 lb	86.18 kg
200 lb	90.72 kg
210 lb	95.25 kg
220 lb	99.79 kg
230 lb	104.33 kg
240 lb	108.86 kg
250 lb	113.4 kg
260 lb	117.93 kg
270 lb	122.47 kg
280 lb	127.01 kg
290 lb	131.54 kg
300 lb	136.08 kg

To convert a whole column at once — package weights for a customs form, or a training log — open Convert a list of values, paste one weight per line, and download the result as CSV.

Pounds and ounces to kilograms

A pound has 16 ounces, so 8 ounces is half a pound, not 0.8 of one. Convert the ounces first:

7 lb 8 oz = 7 + 8 ÷ 16 = 7.5 lb = 3.402 kg (3,401.94 g)
5 lb 8 oz = 5.5 lb = 2.495 kg
12 oz = 0.75 lb = 0.3402 kg (340.19 g)

Type the pounds in the first field and the ounces in + ounces. For ounces alone, the ounces to pounds converter gives the decimal pounds; to go from pounds back to ounces, use pounds to ounces.

Quick ways to estimate in your head

Method	150 lb gives	Error
× 0.45359237 (exact)	68.04 kg	—
÷ 2.2	68.18 kg	+0.2%
Halve, then subtract a tenth	67.5 kg	−0.8%
Halve	75 kg	+10%

Halve and subtract a tenth multiplies by 0.45, close enough for a gym plate or a suitcase. For a medicine dose, a shipping invoice or anything you will sign, use the exact factor.

Where the 0.45359237 comes from

In 1959 the United States, the United Kingdom, Canada, Australia, New Zealand and South Africa agreed on a common pound, defined as exactly 0.45359237 kilogram. NIST lists it as an exact value (Handbook 44, Appendix C), so every correct converter gives the same digits; differences between sites come only from rounding.

This is the avoirdupois pound — the one on scales, food labels and shipping weights in the U.S. The troy pound for gold and silver is 0.3732417216 kg, and a pound-force (lbf) is a force, not a mass. One kilogram is 2.20462 lb, 35.274 oz or 0.157 stone.

Frequently asked questions

How many kilograms are in a pound?

Exactly 0.45359237 kilograms. The value has been fixed by definition since 1959, so it is not a measurement and never changes. For everyday use, 0.4536 kg is accurate to better than one part in 10,000.

Is 1 kg 2.2 pounds?

Close: 1 kg is 2.20462 pounds. Dividing by 2.2 instead of 2.20462 overstates the kilograms by about 0.2% — 150 lb comes out as 68.18 kg instead of 68.04 kg, which matters only when you need the exact figure.

How do I convert pounds and ounces to kilograms?

Turn the ounces into a fraction of a pound first — divide them by 16 — then multiply by 0.45359237. A baby of 7 lb 8 oz weighs 7.5 lb, which is 3.402 kg or 3,402 grams. Enter the ounces in the second field and the converter does both steps.

How many kg is 150 lbs?

150 pounds is 68.04 kilograms (68.0388555 kg exactly). 100 lb is 45.36 kg, 200 lb is 90.72 kg and 300 lb is 136.08 kg.

What is the fastest way to convert lbs to kg in my head?

Halve the pounds, then take away a tenth of the result: 150 → 75 → 75 − 7.5 = 67.5 kg. It is within 1% of the exact 68.04 kg. Dividing by 2.2 is closer still but harder to do mentally.

Is a pound in the US the same as a pound in the UK?

Yes. The United States, the United Kingdom and other Commonwealth countries agreed on the same international pound of 0.45359237 kg in 1959. The troy pound used for precious metals is a different, smaller unit (0.3732 kg).