Length Converter
Convert between all 9 length units — Millimeter, Centimeter, Meter, Kilometer, Inch, Foot, Yard, Mile, Nautical Mile — with instant results, formulas and worked examples.
A single converter for every length unit on ConvertWorks. Pick any two units, type a value, and get an instant, accurate result — no page reloads and nothing leaves your browser. Dedicated pages for the most popular pairs are linked below.
Quick reference — Millimeters to Centimeters
Every unit above is defined relative to the meters: pick any pair and the converter divides the two base factors, so results stay consistent across the whole category.
How to use this calculator
- Choose the unit you have in the From dropdown.
- Choose the unit you want in the To dropdown.
- Type your value — the result updates instantly.
- Use Swap to reverse the conversion, or open a dedicated pair page below for one specific conversion.
The formula
Result = Value × (from-unit factor ÷ to-unit factor), with all factors relative to the meters.
Worked example
10 km = 6.21371 mi — in full, 10 Kilometers converts to 6.21371 Miles. Road distances, room dimensions and race lengths are the everyday jobs for this conversion.
Frequently Asked Questions
What units does this length converter include?
It covers Millimeter, Centimeter, Meter, Kilometer, Inch, Foot, Yard, Mile, Nautical Mile — 9 units in total. Every conversion runs through the meters as the common reference, so any pair you pick stays consistent with every other pair.
How does this length converter work?
Each unit is defined by an exact factor relative to the meters. To convert, the tool multiplies your value by the from-unit's factor and divides by the to-unit's factor, then rounds the display to six significant figures.
How accurate are the results?
The factors come from the official definitions of the units (for example, 1 inch is exactly 0.0254 meters and 1 pound is exactly 0.45359237 kilograms), so conversions are as accurate as the definitions themselves. Display rounding to six significant figures can hide trailing digits on extreme values.
Can I convert Kilometers to Miles with this tool?
Yes — select Kilometers and Miles in the dropdowns. For example, 10 Kilometers equals 6.21371 Miles, and the dedicated pair page linked below focuses on just that conversion.