Weight & Mass Converter
Convert between 10 units of weight and mass. Kilograms, pounds, grams, ounces, stone, metric tons, short and long tons, carats, and milligrams.
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About the Weight & Mass Converter
Mass and weight are related but distinct concepts. Mass is the amount of matter in an object (measured in kg), while weight is the gravitational force acting on that mass (measured in newtons). In everyday usage they are used interchangeably. The kilogram was redefined in 2019 in terms of Planck's constant, making it the most precisely defined unit in history.
Quick facts
- ›The kilogram was redefined on 20 May 2019 using Planck's constant (6.626 × 10⁻³⁴ J·s)
- ›One pound is defined as exactly 0.45359237 kilograms
- ›The carat used for gemstones equals exactly 0.2 grams (200 milligrams)
- ›A metric ton (1,000 kg) differs from a US short ton (907.18 kg) and a UK long ton (1,016 kg)
Common uses: Cooking, shipping logistics, fitness tracking, jewellery, pharmacy, agriculture