Weight & Mass Converter

Convert between milligrams, grams, kilograms, metric tons, ounces, pounds, stones, and more instantly.

Common Weight Conversions
FromToResult
1 KilogramPounds2.20462 lb
1 PoundKilograms0.453592 kg
1 KilogramOunces35.274 oz
1 OunceGrams28.3495 g
1 StoneKilograms6.35029 kg
1 StonePounds14 lb
1 Metric TonKilograms1,000 kg
1 Short TonKilograms907.185 kg

Frequently Asked Questions

One kilogram equals 2.20462 pounds. Conversely, one pound equals 0.453592 kilograms. The kilogram is the SI base unit of mass, while the pound is used in the US customary and imperial systems.

Mass is the amount of matter in an object (measured in kg or lb) and does not change with location. Weight is the force exerted on a mass by gravity and varies by planet or altitude. In everyday use these terms are used interchangeably, but scientifically they are different quantities.

A stone is a unit of weight used in the UK and Ireland equal to 14 pounds or 6.35029 kilograms. It is commonly used for body weight in the UK. So a person weighing 70 kg is approximately 11 stone.

A metric ton (tonne) = 1,000 kg = 2,204.62 lb. A short ton (US ton) = 2,000 lb = 907.185 kg. A long ton (UK ton) = 2,240 lb = 1,016.05 kg. The metric ton is used internationally; the short ton is common in the United States.

Multiply pounds by 0.453592 to get kilograms. For a quick estimate, divide pounds by 2.2. For example, 150 lb ÷ 2.2 ≈ 68.2 kg (exact: 68.039 kg). To convert kg to lb, multiply by 2.20462.

The stone is a unit of weight used mainly in the UK and Ireland for measuring body weight. One stone equals exactly 14 pounds or 6.35029 kg. A person weighing 11 stone 4 pounds is 72.12 kg. The stone is not used in the United States or Canada.

A troy ounce = 31.1035 grams, used for precious metals (gold, silver, platinum). An avoirdupois ounce = 28.3495 grams, used for everyday goods. Troy ounces are about 10% heavier. When you see gold priced "per ounce," it always means the troy ounce.

For a quick mental conversion from kg to lb, multiply by 2 and add 10% (e.g., 70 kg → 140 + 14 = 154 lb; exact: 154.32 lb). For lb to kg, divide by 2 and subtract 10%. These mental shortcuts are accurate to within about 1–2%.

A metric ton and tonne are exactly the same: both equal 1,000 kilograms. "Tonne" is the spelling used in the International System of Units (SI) and by most countries, while "metric ton" is the term often used in the United States to distinguish it from the short ton (907 kg) and long ton (1,016 kg).

Mass is the amount of matter in an object, measured in kilograms, and stays constant regardless of location. Weight is the gravitational force on that mass (W = mg), measured in newtons, and changes with gravity. You weigh less on the Moon but your mass is the same — a 70 kg person weighs 686 N on Earth but only 114 N on the Moon.

About This Weight Converter

This free weight and mass converter converts between kilograms, grams, milligrams, tonnes, pounds, ounces, stones, and other units. Enter a value in any unit and all others update instantly.

When to use this converter

  • Converting body weight between kg and lbs
  • Calculating shipping weights for parcels and freight
  • Converting ingredient quantities in international recipes

Standards & References

How It Works

Enter a Value

Type any weight value. The converter supports whole numbers, decimals, and scientific notation.

Select Units

Pick source and target weight units from the dropdowns. Use the swap button to reverse direction.

Instant Conversion

Results appear instantly using precise conversion factors from international standards.

Common Use Cases

Health & Fitness

Convert body weight between kilograms, pounds, and stones for fitness tracking, BMI calculations, and communicating with doctors in different countries.

Shipping & Logistics

Convert package weights between kilograms and pounds for international shipping rates, customs declarations, and airline baggage allowances.

Cooking & Recipes

Convert ingredient weights between grams, ounces, and pounds when using international recipes that specify different measurement systems.

Agriculture & Industry

Convert bulk commodity weights between metric tons and short tons for trading, pricing, and capacity calculations in industrial applications.

E-commerce

Convert product weights for international listings, ensuring accurate shipping cost calculations for customers in different countries.

Science & Education

Convert mass values between SI and imperial units for physics, chemistry, and engineering coursework or laboratory measurements.

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