Length Converter
Convert length units
Convert length units Runs locally in your browser
About the
The Length Converter translates between nine units: metres, kilometres, centimetres, millimetres, miles, yards, feet, inches and nautical miles. Every metric unit is a clean power of ten, while the imperial units are defined by exact modern values: an inch is exactly 2.54 centimetres and a mile is exactly 1609.344 metres, so there is no ambiguity or rounding in the factors themselves. Nautical miles are a separate system again, fixed at 1852 metres and derived from one minute of latitude.
Where people use the
- Converting a height given in feet and inches into centimetres.
- Working out a running distance in miles from a figure in kilometres.
- Checking a dimension on a drawing supplied in imperial units.
- Converting depth soundings or chart distances in nautical miles.
How to use the
- 1
Enter a value
Type any number, including decimals.
- 2
Choose the unit you have
Pick from the nine available units.
- 3
Choose the unit you want
The result appears immediately and you can swap the direction without retyping.
- 4
Check the order of magnitude
Converting metres to feet should roughly triple the number, and feet to metres should roughly divide it by three. A result that is out by a factor of ten means the wrong unit was selected.
Tips and best practices
- Metres to feet is roughly times three; use that as your quick sanity check.
- Do not use a length conversion for area or volume; the factor is squared or cubed.
- Convert feet and inches into inches first, then into metric, to avoid two-step errors.
Frequently asked questions
How many feet are in a metre?
About 3.2808. Exactly, one foot is 0.3048 metres, so one metre is 1 divided by 0.3048 feet.
Are these conversions exact?
The imperial units have exact modern definitions in metric terms: an inch is exactly 25.4 millimetres, a yard exactly 0.9144 metres and a mile exactly 1609.344 metres. Any difference between tools is rounding in the display, not in the factor.
What is a nautical mile for?
Navigation. It is defined as 1852 metres and corresponds to one minute of latitude, which makes chart and chart-plotter arithmetic work in degrees. It is about 1.15 statute miles.
Why do US survey distances differ slightly?
The US survey foot is marginally longer than the international foot, by about two parts per million. It matters only in surveying and geodesy; for everyday conversion use the international foot, which is what this tool uses.
Can I convert area or volume with this?
No. Converting square or cubic units is not the same as converting lengths: one square metre is about 10.76 square feet, not 3.28. Use the area and volume converters for those.