Length Converter
The Length Converter converts any length value between 9 common units. Enter a number, pick the unit you have and the unit you want, and the result updates instantly in your browser — nothing is uploaded. Every factor below is a standard, exact conversion.
Calculator
The formula
Each unit is defined by how it relates to one metre (the base unit). A value is first converted to the base unit, then to the target unit:
result = ( value × from-factor + from-offset − to-offset ) ÷ to-factor
For simple units the offset is zero, so it reduces to value × from-factor ÷ to-factor. The offset term is what makes temperature scales (which don't share a zero point) convert correctly.
Worked example
Convert 5 km to mi: choose km as From and mi as To, enter 5, and the answer appears immediately with a rounded and a full-precision figure.
Frequently asked questions
- Are these length conversion factors exact?
- Yes. The factors are the internationally standardised definitions (for example 1 inch = 0.0254 m exactly), not rounded approximations.
- Does my data leave my device?
- No. The calculation runs entirely in your browser with JavaScript — nothing is sent to a server.
- Why show two figures?
- The headline is the full-precision result; the “Rounded” figure is a friendlier 2-decimal version for everyday use.
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