Enter a value, pick the unit you have and the unit you want, and get the answer instantly — plus the same value in every other unit at once. It covers the metric units used here and the imperial units you meet in foreign products, sport and travel. Everything runs in your browser.
In all units
- Millimeter (mm)1,000,000 mm
- Centimeter (cm)100,000 cm
- Meter (m)1,000 m
- Kilometer (km)1 km
- Inch (in)39,370.07874 in
- Foot (ft)3,280.839895 ft
- Yard (yd)1,093.613298 yd
- Mile (mi)0.621371 mi
- Nautical mile (nmi)0.539957 nmi
How it works
Each unit is defined by how many metres it equals, so every conversion goes through metres as a common base: your value is turned into metres and then into the target unit. That keeps results consistent — converting kilometres to miles and back returns exactly what you started with.
The conversions use exact international definitions: one inch is 0.0254 m, one mile is 1,609.344 m, and one nautical mile is 1,852 m. Results are shown to six decimals, with trailing zeros trimmed, which is precise enough for everyday and most technical use.
Practical examples
Kilometres to miles for a road trip
A 350 km drive is about 217.48 miles — useful when a foreign GPS or car shows miles. Enter 350, from kilometres, to miles.
Inches to centimetres for a TV
A 55-inch TV is 139.7 cm across the diagonal. Convert inches to centimetres to check it fits the wall space you measured in cm.
Height in feet and inches
To read a height given as 6 ft, convert to metres (1.8288 m) — or enter 185 cm and read it in feet to compare with a foreign form.
Frequently asked questions
How many kilometres are in a mile?
One mile is exactly 1.609344 kilometres, and one kilometre is about 0.621371 miles. The tool uses the exact international definition, so long distances stay accurate rather than drifting from a rounded factor.
How do I convert inches to centimetres?
Multiply inches by 2.54, since one inch is defined as exactly 2.54 cm. Enter your value in inches and read the centimetre row — the tool does it precisely.
What is a nautical mile and how is it different?
A nautical mile is 1,852 metres, used in sea and air navigation because it corresponds to one minute of latitude. It is longer than a land (statute) mile of 1,609.344 m — the tool includes both so they’re never confused.
Why show the value in every unit at once?
It saves repeated conversions and helps you sanity-check a result. When you enter a value, the list underneath shows it in all supported units, with the chosen target highlighted.
How precise are the results?
Conversions are computed at full floating-point precision using exact unit definitions, and displayed to six decimal places with trailing zeros removed. For engineering work needing more digits, use the raw factors noted in this page.
Does it handle decimals and the Serbian comma?
Yes. You can type 6,5 or 6.5 and both mean six and a half. Thousand separators in pasted values are handled too, so a figure like 1.234,5 is read correctly.
Can I convert distances like 5K running races?
Yes — a 5K is 5 kilometres, which is about 3.106856 miles. Marathon distance (42.195 km) comes to roughly 26.22 miles. Enter the kilometre value and read the miles row.
Are the values I enter sent anywhere?
No. The conversion runs entirely in your browser; nothing is uploaded and analytics never receives the numbers.
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