Weight Converter
Convert between metric, imperial, and specialty weight/mass units — kilograms to pounds, ounces to grams, stones and tons, plus carats and grains — with every unit updating live as you type.
Common Weight Conversions
- 1 kilogram = 2.20462 lb
- 1 pound = 0.453592 kg
- 1 ounce = 28.3495 g
- 1 stone = 6.35029 kg
- 1 metric ton = 1,000 kg
- 1 US ton = 907.185 kg
- 1 UK ton = 1,016.05 kg
Understanding Weight & Mass Units
The kilogram is the SI base unit of mass, with grams, milligrams, and metric tons scaling by powers of 10. The imperial/US customary system builds up from the ounce and pound instead: 16 ounces to a pound, 14 pounds to a stone (used mainly in the UK and Ireland for body weight), and 2,000 pounds to a US 'short' ton. Nearly every country now uses the metric system for trade and science, with the pound and ounce persisting mainly in the United States for everyday use.
A US short ton (2,000 lb / 907.185 kg) and a UK long ton (2,240 lb / 1,016.05 kg) are easy to confuse, since both are simply called 'ton' in everyday speech — always check which one a source means when the number matters, as the difference is over 10%. The metric tonne (1,000 kg) sits between the two and is the version used almost everywhere outside the US and UK for shipping and freight. The carat, by contrast, is a unit of precision: fixed at exactly 200 milligrams since 1907, it's used worldwide to weigh gemstones and pearls, where even a fraction of a carat significantly affects value.
Disclaimer: This converter is provided for general informational and reference purposes only. For applications where precision matters — medical dosing, engineering, construction, or legal and regulatory submissions — verify the result independently or consult a qualified professional.
Frequently Asked Questions
About this calculator
This weight converter lets you enter a value in any of 11 units and see it instantly converted to all the others — from milligrams up to tons, including stones, carats, and grains. It covers the metric system, the imperial/US customary system, and specialty units used in jewelry and ammunition, so you don't need to remember conversion factors or do the math by hand.
- 11 units at once — Milligrams, grams, kilograms, metric tons, ounces, pounds, stone, US (short) tons, UK (long) tons, carats, and grains, all converted simultaneously.
- Live conversion — Type a value into any unit and every other field updates instantly — no need to click a button or pick a 'from' and 'to' unit.
- US and UK tons both included — Correctly distinguishes the US short ton (2,000 lb) from the UK long ton (2,240 lb) — two different units that are often confused under the same name.
- Precision units for jewelry — Carats and grains are built in alongside everyday units, for weighing gemstones, precious metals, and ammunition components accurately.
- Quick reference table — Common conversions (kg to lb, oz to g, and more) are listed for fast lookup without typing anything.