Length Converter
Convert between metres, kilometres, miles, feet, inches, yards and more. Length is the most common measurement, used in everyday life, construction and science.
Written by Rahman · Last reviewed
Quick answer
Length conversion runs through the metre. One kilometre is 0.621 miles, one metre is 3.281 feet, one inch is exactly 2.54 centimetres and one mile is exactly 1,609.344 metres. The inch has been defined as exactly 2.54 cm since 1959, so imperial-to-metric length conversion is exact rather than approximate.
| Metre (m) | 1 |
| Kilometre (km) | 0.001 |
| Decimetre (dm) | 10 |
| Centimetre (cm) | 100 |
| Millimetre (mm) | 1000 |
| Micrometre (µm) | 1000000 |
| Nanometre (nm) | 1000000000 |
| Mile (mi) | 0.0006213711922 |
| Yard (yd) | 1.093613298 |
| Foot (ft) | 3.280839895 |
| Inch (in) | 39.37007874 |
| Nautical mile (nmi) | 0.0005399568035 |
| Light year (ly) | 1.057001e-16 |
Common conversions
| 1 km | 0.621 mi |
| 2 km | 1.243 mi |
| 5 km | 3.107 mi |
| 10 km | 6.214 mi |
| 25 km | 15.53 mi |
| 50 km | 31.07 mi |
| 100 km | 62.14 mi |
| 1 cm | 0.394 in |
| 2 cm | 0.787 in |
| 5 cm | 1.969 in |
| 10 cm | 3.937 in |
| 25 cm | 9.843 in |
| 50 cm | 19.69 in |
| 100 cm | 39.37 in |
| 1 m | 3.281 ft |
| 2 m | 6.562 ft |
| 5 m | 16.4 ft |
| 10 m | 32.81 ft |
| 25 m | 82.02 ft |
| 50 m | 164 ft |
| 100 m | 328.1 ft |
Popular conversions
Embed this converter on your site
A fixed-height frame — simplest option, works everywhere. Free to embed anywhere. The "Powered by A2Z Calc" link may not be removed.
About the Length Converter
Length measures distance: how far apart two points are. The metric system uses metres, with kilometres, centimetres and millimetres as common multiples, while the imperial system uses miles, yards, feet and inches. Converting between the two is needed constantly in travel, construction, engineering and everyday life.
This tool converts any length value instantly and shows the equivalent in every supported unit, so you can move between metric and imperial figures without manual calculation.
Nautical miles are a different unit entirely
A nautical mile is not a variant of the statute mile used on roads. It is defined from the geometry of the Earth rather than from historical land measures, and it is substantially longer.
One nautical mile is exactly 1,852 metres, against 1,609.344 metres for the statute mile. That makes it 15.1% longer, so a distance of 100 nautical miles is about 115 statute miles. Marine and aviation distances use it because one nautical mile corresponds to one minute of latitude, which makes chart work straightforward.
- Speeds in those contexts are quoted in knots, which are nautical miles per hour, so a knot is likewise about 1.15 mph.
- Aviation and marine reports mix units freely: altitude in feet, distance in nautical miles, visibility in statute miles.
- Converting a marine distance with the statute mile figure understates it by roughly 15%, which is a navigational error rather than a rounding one.
The foot has had more than one definition
The international foot has been exactly 0.3048 metres since 1959, and that is the value this converter uses. Before that agreement, the US used a slightly different definition (the survey foot) based on the older relationship of 39.37 inches to the metre.
The difference is about two parts per million, which is invisible in ordinary use and significant in land surveying. Over a distance of 100 kilometres it amounts to roughly 20 centimetres, which is enough to move a boundary.
- US survey feet were formally deprecated at the end of 2022 in favour of the international foot.
- Older US survey data, plat maps and state plane coordinate systems may still be expressed in survey feet.
- For everyday conversions the distinction is irrelevant; for legal boundaries and geodetic work, check which definition the source used.
Frequently Asked Questions
How many feet are in a metre?
⌄
One metre equals approximately 3.28084 feet, or 39.3701 inches.
How do I convert kilometres to miles?
⌄
Multiply kilometres by 0.621371 to get miles. For example, 10 km is about 6.21 miles.
What is the difference between metric and imperial length?
⌄
Metric units (metre, kilometre) are based on powers of ten, while imperial units (foot, mile) use varied ratios. Most countries use metric; the US still uses imperial widely.