Pounds vs Kilograms: Key Differences Explained
Compare pounds and kilograms to understand weight conversions between the imperial and metric systems.
Quick Answer
1 kilogram equals 2.205 pounds. Pounds are used in the US; kilograms are the global standard.
| Feature | Pounds (lb) | Kilograms (kg) |
|---|---|---|
| Imperial unit used in the US | Metric unit used by most of the world | |
| 1 pound = 0.4536 kilograms | 1 kilogram = 2.205 pounds | |
| Subdivided into 16 ounces | Subdivided into 1,000 grams | |
| Used for body weight in US | Used for body weight internationally and in medicine |
The pound is the standard unit of weight in the United States, used for body weight, groceries, shipping, and everyday measurement. One pound equals 16 ounces or approximately 0.454 kilograms.
The kilogram is the base unit of mass in the metric system and the international standard for measuring weight. Its decimal subdivision into grams makes calculations simple, which is why medicine and science use kilograms exclusively.
When to Use Pounds (lb)
- Everyday weight measurement in the United States
- US cooking recipes and grocery shopping
- Shipping and freight in the US
When to Use Kilograms (kg)
- International communication and travel
- Medical and scientific contexts
- Weightlifting (many gyms use kg plates)
Worked Example
A person weighs 180 pounds.
Pounds (lb)
In pounds: 180 lbs.
Kilograms (kg)
In kilograms: 180 / 2.205 = 81.6 kg.
Divide pounds by 2.205 to get kilograms, or multiply kg by 2.205 to get pounds.
Related Comparisons
Frequently Asked Questions
Is a pound mass or force?
In everyday use, pounds refer to mass. In physics, pound-force (lbf) and pound-mass (lbm) are distinguished.
Why does the UK use both?
The UK officially uses metric but many people still think in stones and pounds for body weight.
What is a stone?
A stone is 14 pounds (6.35 kg), commonly used in the UK and Ireland for body weight.