Pounds to Kilograms Converter
Convert pounds to kilograms instantly. Type a lbs value and get the exact kg result. Formula: 1 lb = 0.453592 kg.
Converting pounds to kilograms is perhaps the most frequent metric-imperial weight translation needed by Americans travelling or communicating internationally. While the US uses pounds for nearly all everyday weight references, virtually every other country — and nearly all scientific, medical, and engineering contexts globally — uses kilograms. The precise conversion factor is 1 lb = 0.45359237 kg, which is the internationally agreed definition of the avoirdupois pound. This means 100 lbs equals 45.36 kg, a figure that comes up constantly in fitness contexts — a 225-pound squat personal record is a 102 kg lift, which crosses the 100 kg psychological threshold beloved by strength athletes. In medicine, patient weights are almost universally recorded in kilograms, and drug dosing calculations are done per kilogram of body weight. A patient reporting a 150-pound weight to a physician will have that converted to 68.04 kg for dosing purposes. Infant weights at birth are given in grams and kilograms in most of the world. For international shipping and customs, weights in kg are the standard. A parcel declared at 5 lbs is 2.27 kg under international customs documentation. The quick mental conversion: divide pounds by 2.2 to approximate kilograms.
Related Conversions
Free Online Unit Converter
Zolkit's unit converter supports 7 categories covering dozens of the most common conversions — length, weight, temperature, volume, area, speed, and torque. Pick a category, select your units from the dropdowns, type a value, and see the result instantly. A swap button reverses the conversion direction with one click. Your last-used category and units are remembered locally so the converter is ready when you return.
7 Unit Categories
Convert length, weight, temperature, volume, area, speed, and torque — all the unit conversions you need in one tool.
Instant Conversion
Results update as you type. Switch between units with dropdowns and see the converted value immediately.
Swap Units
Hit the swap button to instantly reverse the conversion direction. Saves time when you need both directions.
Offline-Ready
All conversions are calculated locally in your browser. No internet required after the page loads.
Works on Any Device
Clean, responsive layout that works on phones, tablets, and desktops alike.
Always Free
No account required, no ads, no limits. Convert as many units as you need, whenever you need.
How to Use the Unit Converter
- 1
Choose a unit category from the tab bar at the top: Length, Weight, Temperature, Volume, Area, Speed, or Other.
- 2
Select the unit you're converting from and the unit you're converting to using the dropdowns. Type your value and the result appears instantly.
- 3
Click the swap button (↔) to reverse the conversion direction, or click Copy to save the result to your clipboard.
Frequently Asked Questions
How many kilograms is 1 pound?
1 pound equals exactly 0.45359237 kilograms. This is the international definition of the avoirdupois pound, adopted in 1959.
What is 150 lbs in kg?
150 lbs equals 68.04 kg (150 × 0.453592 = 68.039). This is a common benchmark weight in fitness and medical records.
How do I convert pounds to kg in my head?
Divide pounds by 2.2 for a quick estimate. For example, 220 lbs ÷ 2.2 = 100 kg. For more accuracy, use 2.205 as the divisor.
Why does the US use pounds instead of kilograms?
The US retained the imperial system after independence rather than adopting the metric system that spread through Europe in the 19th century. All three countries that don't officially use the metric system — the US, Myanmar, and Liberia — use pounds for everyday weight.