Mass Calculator
Convert mass between milligrams, grams, kilograms, metric tons, ounces, pounds, stone, and more. See all conversions at once in a clean table.
About the Mass Calculator
Mass is a fundamental property of matter, measured in SI units as kilograms. This calculator converts between all common mass units using gram as the intermediate base. Key conversions: 1 lb = 453.592 g, 1 kg = 2.2046 lb, 1 stone = 14 lb = 6.350 kg, 1 metric ton = 1,000 kg, 1 short ton (US) = 2,000 lb = 907.185 kg. For a broader set of unit conversions including length, volume, and temperature, visit the Unit Conversion Calculator.
Mass and weight are often confused — mass measures the amount of matter (invariant), while weight is the gravitational force acting on that mass (varies by location). On Earth, 1 kg of mass weighs approximately 9.807 Newtons. To explore weight in different gravitational fields including other planets, try the Weight Calculator. For body weight context, our BMI Calculator uses kg and lbs directly.
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For a related calculation, use Weight Calculator to convert weight units (kg, N, lbf, kgf) and calculate your weight on other planets and the Moon. Alternatively, use Tire Size Calculator to decode tire size codes like 225/55R17 to get sidewall height, overall diameter, and circumference.
For the underlying method, read Unit Conversion Guide: Metric, Imperial, and the Math That Connects Them.