Pounds to Kilograms

What Is Lbs to Kg Conversion?

Converting pounds to kilograms is essential when dealing with international standards, shipping abroad, or communicating with the 95% of the world that uses the metric system. This tool makes that conversion instant and accurate.

When You Need This Conversion

• International shipping — Customs forms require weights in kilograms
• Medical records — Many countries record patient weights in kg
• Scientific contexts — Research and academia use metric exclusively
• International travel — Understanding local weight measurements
• Importing goods — Product specifications often listed in kg
• Sports — Olympic and international competitions use kg

The Conversion Factor

One pound equals exactly 0.45359237 kilograms. For quick mental math, divide pounds by 2.2 to get an approximate kilogram value.

The Global Standard

The kilogram is the SI (International System of Units) base unit for mass, defined by fundamental physical constants since 2019. It's the legal standard for trade in nearly every country.

How to Convert Lbs to Kg

Using This Converter

1. Enter the weight in pounds in the left field
2. The equivalent in kilograms appears instantly
3. Click swap to convert from kg to lbs instead
4. Use copy to paste the result into forms or documents

Quick Mental Math

• Divide by 2.2 — Fast approximation
• Halve and subtract 10% — 100 lbs ÷ 2 = 50, minus 5 = 45 kg (actual: 45.4)

Common Reference Points

• 1 lb = 0.45 kg (about half a kg)
• 10 lbs = 4.5 kg (a bag of potatoes)
• 50 lbs = 22.7 kg (checked baggage limit)
• 100 lbs = 45.4 kg (half a person's weight)

For Customs Forms

When shipping internationally, customs declarations require weights in kilograms. Convert your package weights precisely to avoid delays or duty miscalculations.

Features & Use Cases

Instant Bidirectional Conversion

Switch between lbs→kg and kg→lbs with one click. Perfect when you need to convert in both directions while filling out forms.

Common Use Cases

International Shipping

USPS, FedEx, and DHL customs forms require kilogram weights. Accurate conversion ensures proper duty calculation and avoids package delays.

Medical & Healthcare

If you're seeing a doctor abroad or sharing medical records internationally, weights must be in kilograms. Drug dosages are often calculated per kg of body weight.

Fitness & Sports

International gyms, Olympic competitions, and European fitness programs use kilograms. Convert your familiar pound weights to participate confidently.

E-commerce & Importing

Products from Europe, Asia, and most of the world list specifications in kilograms. Convert to understand what you're buying.

Scientific & Academic

All scientific research uses SI units. If you're referencing American data in international contexts, conversion to kg is mandatory.

Gym Weight Reference

The built-in table shows common gym plate weights, helping athletes understand international equipment standards.

Frequently Asked Questions

How many kilograms are in a pound?

One pound equals exactly 0.45359237 kilograms. For quick math, divide by 2.2.

Why do customs forms need kilograms?

International trade uses the metric system. The World Trade Organization and international postal unions standardized on kilograms for consistent commerce.

How do I convert my weight for a doctor abroad?

Divide your weight in pounds by 2.2. A 175 lb person weighs approximately 79.4 kg. Round to 79 kg for medical forms.

Is 1 pound exactly 0.45 kg?

Close but not exact. 1 lb = 0.45359237 kg. The 0.45 approximation is within 1% accuracy, fine for everyday use but not for precise applications.

What's 200 lbs in kg?

200 pounds equals 90.72 kilograms. This is a common reference point — roughly 91 kg.

Why don't American products show kilograms?

While the US officially recognizes metric units, labeling laws don't require them. Many products now show both units, but pounds remain the primary measure for consumers.