How to Convert Pounds to Kilograms (lbs to kg)

The Pounds to Kilograms Formula

The pound (lb) is the primary unit of weight in the imperial system, while the kilogram (kg) is the base unit of mass in the metric system. The exact conversion is:

1 pound = 0.453592 kilograms

To convert pounds to kg: multiply by 0.453592. To convert kg to pounds: multiply by 2.20462.

Quick Reference Table

• 1 lb = 0.454 kg
• 5 lbs = 2.268 kg
• 10 lbs = 4.536 kg
• 50 lbs = 22.68 kg
• 100 lbs = 45.36 kg
• 150 lbs = 68.04 kg
• 200 lbs = 90.72 kg

Common Use Cases

Body weight: If you weigh 154 lbs, that's 70 kg. If someone says they weigh 80 kg, that's about 176 lbs.

Gym and fitness: A 45-lb barbell plate is about 20.4 kg. A 25-lb dumbbell is roughly 11.3 kg.

Cooking and shipping: Recipe ingredients or package weights are often listed in one system and need converting for international use.

A Quick Mental Shortcut

To roughly convert kg to pounds in your head, multiply by 2 and add 10%. So 70 kg × 2 = 140, plus 10% (14) = 154 lbs. This gives a result within about 0.2% of the exact answer.

For exact conversions, use our free weight converter.

Step-by-Step Conversion Examples

Converting Body Weight for a Medical Form

You weigh 165 lbs and a doctor's intake form asks for weight in kilograms:

165 lbs × 0.45359237 = 74.843 kg

Verification: 74.843 × 2.20462 = 165.0 lbs ✓

The exact factor is 0.45359237 kg per pound — fixed by the International Yard and Pound Agreement of 1959, signed by the US, UK, Canada, Australia, New Zealand, and South Africa. For everyday rounding: 165 lbs ÷ 2.2 = 75 kg (within 0.2% of the exact answer).

Converting Gym Weights

A standard Olympic barbell plate in a US gym is labeled 45 lbs. How heavy is it in kg?

45 lbs × 0.45359237 = 20.412 kg

International weightlifting uses 20 kg plates as the standard — close to but not identical to 45 lbs (which is 20.41 kg). A world-record 200 kg clean-and-jerk = 440.9 lbs; a 100 lb deadlift = 45.36 kg. Competitive lifters track records in both systems.

International Airline Baggage Limits

Most international airlines allow 23 kg for checked baggage. A US traveler packing in pounds needs to know:

23 kg × 2.20462 = 50.71 lbs

The 23 kg international standard ≈ 50.7 lbs. Some US carriers use a 50 lb limit, which equals 22.68 kg — slightly less than the 23 kg international standard. Always verify the exact limit with your airline before travel to avoid overweight fees.

Cooking: Scaling a Recipe

A UK recipe calls for 2.5 lbs of beef brisket. Your scale reads in grams:

2.5 lbs × 453.592 g = 1,133.98 g ≈ 1,134 g

Round to 1,130–1,135 g for practical kitchen purposes. For reference: 1 lb = 453.592 g, so 0.5 lb (8 oz) = 226.8 g. Baking recipes that specify weight in ounces: 1 oz = 28.35 g (always avoirdupois ounces, not troy ounces).

Source: International Bureau of Weights and Measures (BIPM); International Pound and Kilogram Agreement (1959). Last verified: May 2026.