Length Converter
The Length Converter helps you convert measurements between millimetres, centimetres, metres, kilometres and miles. It is useful for school work, travel planning, maps, product sizes, building measurements, fitness distances and many everyday tasks.
How to use this length converter
Enter a value in any one field and the other fields update with the matching measurements. You can start with a small unit such as millimetres or centimetres, or a larger unit such as kilometres or miles.
Why length conversion matters
Different countries and industries use different units. A clear converter helps you compare measurements quickly without manual math.
Enter a value in any field to convert it into millimetres, centimetres, metres, kilometres and miles.
Common length units
Millimetres and centimetres are often used for small objects, product sizes and short measurements. Metres are common for room sizes, height and building measurements. Kilometres and miles are used for longer distances, travel routes, road distances and map information.
Quick reference
| Unit | Common use | Basic relationship |
|---|---|---|
| Millimetre | Very small measurements | 10 millimetres = 1 centimetre |
| Centimetre | Object sizes and short lengths | 100 centimetres = 1 metre |
| Metre | Height, rooms and building work | 1,000 metres = 1 kilometre |
| Kilometre | Roads, maps and travel distance | 1 kilometre is about 0.621 miles |
| Mile | Road and travel distance in some countries | 1 mile is about 1.609 kilometres |
When this tool is useful
Use this page when reading product details, comparing travel distances, checking a map, doing school work, measuring a room, preparing a report, or converting measurements from another country.
Frequently asked questions
Can I convert miles to kilometres?
Yes. Enter the mile value and the kilometre value will appear.
Can I convert centimetres to metres?
Yes. Enter the centimetre value and the matching metre value will be shown.
Does the converter update all fields?
Yes. Enter one value and the matching values appear in the other units.