How to Convert Pounds to Kilograms
Pounds (lb) and kilograms (kg) are the two most common units of body weight worldwide. Americans typically use pounds while most of the world uses kilograms, so this conversion comes up constantly in travel, medicine, fitness, and international shipping.
The exact conversion is 1 pound = 0.453592 kilograms. You can also remember the rough shortcut: divide by 2.2 to go from pounds to kilograms.
The Conversion Formula
Kilograms = Pounds ร 0.453592
Or using the shortcut:
Kilograms โ Pounds รท 2.2
Step-by-Step Example
You weigh 165 lb and need to fill out a medical form asking for your weight in kg.
- Use the formula: 165 ร 0.453592
- Result: 74.84 kg
Using the shortcut: 165 รท 2.2 = 75 kg (close, but 74.84 is more precise).
Pounds to Kilograms Reference Table
| Pounds | Kilograms |
|---|---|
| 100 lb | 45.36 kg |
| 120 lb | 54.43 kg |
| 140 lb | 63.50 kg |
| 150 lb | 68.04 kg |
| 160 lb | 72.57 kg |
| 175 lb | 79.38 kg |
| 200 lb | 90.72 kg |
Medical and Fitness Context
Medication dosing is often calculated in mg/kg of body weight, making accurate lb-to-kg conversions critical in healthcare. If your doctor prescribes 10 mg/kg and you weigh 180 lb (81.65 kg), your dose would be 816.5 mg.
In fitness, many strength training benchmarks worldwide are expressed in kilograms. Olympic weightlifting weight classes are also defined in kg.
Use our pounds-to-kg calculator for instant, accurate conversions.