Home›Calculators› Unit converterBrowser
Convert between units of length and weight
Converts within length and weight. Every conversion goes through one base unit per group, so the same exact factors are used in both directions.
0.1 cm
1 millimeters = 0.1 centimeters
Common presets
Each one has its own page explaining where that requirement comes from and what to expect.
How to use it
- 1Choose whether you are measuring length or weight.
- 2Pick the unit you have and the unit you want.
- 3Type the amount — the result updates as you type.
Frequently asked questions
- Are the conversions exact?
- The definitions are: an inch is exactly 25.4 mm and a pound is exactly 0.45359237 kg, both fixed by international agreement in 1959. Everything here goes through one base unit per group, so converting there and back returns the number you started with.
- Why do I get a slightly different answer than another calculator?
- Rounding, almost always at the display step. 1 kg is 2.2046226… lb, and a tool that shows two decimals has thrown away the rest before you compare. The underlying factors are the same everywhere; the digits shown are not.
- What is a stone?
- 14 pounds, or about 6.35 kg. It is still the everyday unit for body weight in the UK and Ireland, which is why a British answer to "how much do you weigh" sounds like a two-part number.
- Does it convert areas or volumes?
- No — length and weight only. Area and volume factors are the square and the cube of the length factors, and mixing them into the same picker is where unit-converter bugs come from.