Weight Unit Converter
Convert between different weight and mass units including kilograms, pounds, ounces, and more
Converted to All Units
| Unit | Value |
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Common Weight Conversions
Metric to Imperial
- 1 kilogram = 2.20462 pounds
- 1 gram = 0.03527 ounces
- 1 metric ton = 2,204.62 pounds
- 100 grams = 3.5274 ounces
- 500 grams = 1.1023 pounds
Imperial to Metric
- 1 pound = 0.45359 kilograms
- 1 ounce = 28.3495 grams
- 1 stone = 6.35029 kilograms
- 1 US ton = 907.185 kilograms
- 1 imperial ton = 1,016.05 kilograms
Understanding Weight and Mass Units
Weight and mass are often used interchangeably in everyday language, though scientifically they differ. Mass is an intrinsic property of matter, while weight is the force exerted by gravity on that mass. In common usage and for practical conversion purposes, these terms are treated as equivalent at Earth's surface gravity.
Metric System (SI)
- Milligram (mg): One thousandth of a gram. Used for pharmaceuticals, nutritional information, and small chemical quantities.
- Gram (g): The base unit for small measurements. Common in cooking, nutrition labels, and postal services.
- Kilogram (kg): The SI base unit of mass, equal to 1,000 grams. Defined by the Planck constant since 2019. Used worldwide for body weight, groceries, and general commerce.
- Metric Ton (t): Equal to 1,000 kilograms. Used for large-scale weights in shipping, agriculture, and industry.
Imperial and US Customary
- Ounce (oz): Equal to 1/16 of a pound (approximately 28.35 g). Common in US cooking, food packaging, and postal services.
- Pound (lb): Equal to exactly 0.45359237 kg by international agreement (1959). Widely used in the US and UK for body weight, food, and general commerce.
- Stone (st): Equal to 14 pounds. Primarily used in the UK and Ireland for body weight.
- US Ton (short ton): Equal to 2,000 pounds (907.185 kg). Used in the United States for heavy loads.
- Imperial Ton (long ton): Equal to 2,240 pounds (1,016.05 kg). Historically used in the UK and still used in some maritime contexts.
Troy and Specialty Units
- Troy Ounce (ozt): Equal to approximately 31.1035 g. The standard unit for precious metals such as gold, silver, and platinum.
- Troy Pound (lbt): Equal to 12 troy ounces (373.242 g). Used in the precious metals trade.
- Carat (ct): Equal to 200 mg (0.2 g). The standard unit for gemstone weight.
- Grain (gr): Equal to approximately 64.799 mg. One of the oldest units of weight, still used in ballistics and pharmacology.
Practical Applications
Cooking & Nutrition
- Recipes often mix metric and imperial
- Nutrition labels use grams and milligrams
- Baking requires precise gram measurements
- US recipes use ounces and pounds
Health & Fitness
- Body weight in kg, lbs, or stones
- Medication dosages in mg or g
- Food portion tracking
- BMI calculations require kg
Shipping & Trade
- International shipping uses kilograms
- US domestic shipping uses pounds
- Freight measured in metric or short tons
- Precious metals priced per troy ounce
References
The conversion factors used in this calculator are based on internationally recognized standards and authoritative sources:
Note: All conversion factors are based on internationally agreed-upon definitions. The avoirdupois pound is defined as exactly 0.45359237 kg by the International Yard and Pound Agreement of 1959. The kilogram was redefined in 2019 based on the Planck constant, replacing the original platinum-iridium prototype. Minor rounding may occur when displaying very large or very small values.
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