Quick Answer: Pounds to Kilograms
One pound is approximately 0.4536 kilograms (1 lb ≈ 0.4536 kg).
Conversely, 1 kg ≈ 2.205 lb.
Formula: kg = lb × 0.45359237
Worked examples
- 1 lb ≈ 0.4536 kg
- 5 lb ≈ 2.268 kg
- 10 lb ≈ 4.536 kg
Method and limitations
Multiply pounds by 0.45359237. The international avoirdupois pound is exactly 0.45359237 kg, fixed by the 1959 international yard and pound agreement. Calculations use full-precision constants; answers in this box are rounded for readability (≈ marks a rounded value) and the calculator shows up to 9 significant figures.
Each factor is exact by definition, derived from exact definitions, or a documented conventional value — see the methodology and sources.
Conversion Formula
Multiply pounds by 0.45359237. The international avoirdupois pound is exactly 0.45359237 kg, fixed by the 1959 international yard and pound agreement.
Complete Guide to Pounds to Kilograms Conversion
What is a pound?
The international avoirdupois pound (lb) is exactly 0.45359237 kg and is divided into 16 ounces.
What is a kilogram?
The kilogram (kg) is the SI base unit of mass.
How the Conversion Works
kg = lb × 0.45359237. A bathroom scale reading to 0.2 lb is precise to about 0.1 kg, so more decimals add nothing.
Step-by-Step Conversion Guide
Follow these steps to convert pounds to kilograms manually:
Start with your value in pounds
Example: You want to convert 10 lb
Apply the conversion formula
Use the formula: kg = lb × 0.45359237
Calculate the result
10 lb = 4.5359 kg
Verify your answer
Use our calculator above to double-check your manual calculation.
Quick Mental Math Tip
Halve the pounds and take off 10% of that: 150 lb → 75 − 7.5 = 67.5 kg (exact 68.04 kg).
Common Conversions
| Pounds (lb) | Kilograms (kg) | Kilograms → Pounds |
|---|---|---|
| 1 lb | 0.453592 | 1 kg = 2.20462 lb |
| 5 lb | 2.26796 | 5 kg = 11.0231 lb |
| 10 lb | 4.53592 | 10 kg = 22.0462 lb |
| 20 lb | 9.07185 | 20 kg = 44.0925 lb |
| 50 lb | 22.6796 | 50 kg = 110.231 lb |
| 100 lb | 45.3592 | 100 kg = 220.462 lb |
| 150 lb | 68.0389 | 150 kg = 330.693 lb |
| 200 lb | 90.7185 | 200 kg = 440.925 lb |
| 250 lb | 113.398 | 250 kg = 551.156 lb |
| 500 lb | 226.796 | 500 kg = 1,102.31 lb |
Popular Pounds to Kilograms Conversions
Tap any value to load it into the calculator above.
When You'll Need This Conversion
Body weight
Give a weight in pounds in kilograms for a metric form or record.
Shipping and product weights
Check a parcel or product weight in lb against a carrier or specification limit in kg.
Common Mistakes to Avoid
Dividing by 2
A kilogram is 2.2 lb, not 2 lb; halving overstates kg by about 10%.
200 lb = 90.72 kg, not 100 kg.
Frequently Asked Questions
Related Guides & Articles
View allWant to learn more about weight conversions?
Browse all weight articles →People Also Convert
Related calculators users frequently visit alongside pounds to kilograms.
Conversion factors on this page are either exact by definition, derived from exact definitions, or conventional values in documented use. Each is listed with its source in our conversion methodology and sources, which cites the BIPM SI Brochure, NIST Special Publication 811 and the relevant IEC or national standards. Results are rounded for display only; calculations use full precision.