Pounds to Kilograms Calculator
Enter a weight in pounds or kilograms to see it in both, plus ounces, grams, stone and a stone-and-pounds split. One pound is exactly 0.45359237 kilograms, so 150 lb is 68.0389 kg.
Last updated November 3, 2026
Above 0, up to 1,000,000.
Result
150 lb = 68.0389 kg
| Unit | Amount |
|---|---|
| Pounds | 150 lb |
| Kilograms | 68.0389 kg |
| Ounces | 2,400 oz |
| Grams | 68,038.8555 g |
| Stone | 10.7143 st |
| Stone and pounds | 10 st 10 lb |
Stone and pounds rounds the leftover pounds to 2 decimals. Other values are rounded to 4 decimals for display only.
Show the work
Formula: 1 lb = 0.45359237 kg exactly; kg = lb × 0.45359237; lb = kg ÷ 0.45359237; 1 lb = 16 oz; 1 stone = 14 lb.
- You entered 150 lb.
- Kilograms: 150 × 0.45359237 = 68.0389 kg.
- Ounces: 150 lb × 16 = 2,400 oz.
- Grams: 68.0389 kg × 1,000 = 68,038.8555 g.
- Stone: 150 lb ÷ 14 = 10.7143 st, which is 10 st 10 lb.
Result: 150 lb = 68.0389 kg
How pounds convert to kilograms
kg = lb × 0.45359237
lb = kg ÷ 0.45359237
1 lb = 16 oz
1 stone = 14 lb
1 kg = 1,000 g
The pound used in everyday weighing is the international avoirdupois pound. Since the international yard and pound agreement of 1959 it has been defined as exactly 0.45359237 kilograms, so the conversion is a fixed multiplication rather than an approximation.
To go from pounds to kilograms, multiply by 0.45359237. To go the other way, divide by the same number, which is the same as multiplying by about 2.2046226. The calculator uses the exact figure internally and only rounds what it displays.
The other units hang off the pound. An ounce is one sixteenth of a pound, so ounces are pounds times 16. A stone is 14 pounds, so stone is pounds divided by 14. Grams are kilograms times 1,000.
See how we calculate for the formulas, sources and review schedule behind every calculator.
Quick mental maths
For a rough answer, halve the pounds and then take off a tenth of that half. For 150 lb, half is 75 and a tenth of 75 is 7.5, giving 67.5 kg, close to the true 68.04 kg. Going back, double the kilograms and add a tenth of the result: 70 kg doubles to 140, plus 14 gives 154 lb, against a true 154.32 lb.
These shortcuts are fine for luggage or a rough fitness target. Use the calculator when the figure goes on a form, a prescription label or a shipping document.
Stone and pounds
In the UK and Ireland, body weight is often given in stone and pounds. One stone is 14 pounds, so 150 lb is 10 stone 10 lb, and 70 kg, which is 154.32 lb, is 11 stone and 0.32 lb.
The stone-and-pounds line rounds the leftover pounds to two decimals. If that rounding reaches 14, it is carried over into the stone count, so you never see a leftover of 14 pounds.
Where each unit is used
Kilograms are the SI unit of mass and are used for weight in most countries. Pounds remain common in the United States for body weight, groceries and shipping, and ounces are common for small parcels and food packaging. Gyms often label plates in both pounds and kilograms, which is why conversions come up when you follow a programme written for the other system.
Strictly, pounds and kilograms measure mass, while weight is a force. On Earth the two are used interchangeably in daily life, and this page treats them that way.
Edge cases and limits
The amount must be a finite number above 0 and at most 1,000,000. Zero and negative values are rejected, because a weight to convert is always positive. Decimals are accepted, so 12.5 lb works.
Results are rounded to four decimals for display only, and the copied text uses the same rounded figures. Converting a value and converting the result back can differ in the last displayed digit only because of that rounding.
How to use the Pounds to Kilograms Calculator
- Type the weight you want to convert.
- Choose whether it is in pounds or kilograms under Convert from.
- Read the converted weight, plus ounces, grams, stone and stone and pounds.
- Open Show the work to see each multiplication and division with your numbers.
- Use Copy, Print or Share to keep or send the result.
Worked example
A person weighs 150 lb. Multiplying by 0.45359237 gives 68.0388555 kg, shown as 68.0389 kg. That is also 2,400 oz, 68,038.8555 g and 10.7143 stone, or 10 stone 10 lb.
| Pounds | Kilograms |
|---|---|
| 1 | 0.4536 |
| 5 | 2.268 |
| 10 | 4.5359 |
| 20 | 9.0718 |
| 50 | 22.6796 |
| 100 | 45.3592 |
| 150 | 68.0389 |
| 200 | 90.7185 |
| 250 | 113.3981 |
Frequently asked questions
How many kilograms are in a pound?
One pound is exactly 0.45359237 kilograms, which is about 0.4536 kg or 453.59 grams. This value is fixed by international agreement.
How do I convert kilograms to pounds?
Divide the kilograms by 0.45359237, or multiply by about 2.2046. For example, 70 kg is 154.3236 lb, which is 11 stone and 0.32 lb.
How many pounds are in a stone?
A stone is exactly 14 pounds. So 150 lb is 10 stone 10 lb, and 14 lb is exactly 1 stone.
Is the pound the same in the US and the UK?
Yes. Both use the international avoirdupois pound of 0.45359237 kg. Older troy pounds used for precious metals are different and are not covered here.
How many ounces are in a pound?
There are 16 avoirdupois ounces in a pound, so 1 ounce is 28.349523125 grams. The calculator shows the ounce total for the weight you enter.