Length Converter
Convert everyday length and distance units including millimetres, centimetres, metres, kilometres, inches, feet, yards and miles. Useful for UK metric and imperial conversions like cm to inches, metres to feet and miles to kilometres.
Length converter calculator
Enter a length or distance, choose the starting unit and choose the unit you want to convert to.
Popular length conversions
Use these quick buttons for common UK metric and imperial length conversions.
How length conversion works
Length conversions use a fixed conversion factor. The calculator converts the original value into metres first, then converts metres into the unit you selected.
converted length = original length × conversion factorFor example, 1 inch is exactly 2.54 centimetres. That makes centimetres to inches one of the easiest conversions to remember.
inches = centimetres ÷ 2.54
centimetres = inches × 2.54Common length formulas
| Conversion | Formula | Example |
|---|---|---|
| cm to inches | cm ÷ 2.54 | 10 cm = 3.94 in |
| inches to cm | in × 2.54 | 12 in = 30.48 cm |
| metres to feet | m × 3.28084 | 2 m = 6.56 ft |
| feet to metres | ft × 0.3048 | 6 ft = 1.83 m |
| miles to kilometres | mi × 1.609344 | 5 mi = 8.05 km |
| kilometres to miles | km ÷ 1.609344 | 10 km = 6.21 mi |
UK length and distance notes
In the UK, metric and imperial length units are both common. Product dimensions often use centimetres or millimetres, property and room measurements may use metres or feet, and road distances are usually shown in miles.
- Small measurements: millimetres, centimetres and inches.
- Rooms and height: metres, feet and inches.
- Travel distances: miles and kilometres.
- Sport and outdoor distances: metres, yards, kilometres and miles.
Rounding converted lengths
Converted lengths often produce long decimal answers. For everyday use, round based on the job. A screen size might need one decimal place, while a DIY measurement may need millimetres.
FAQs
How do I convert cm to inches?
Divide centimetres by 2.54. For example, 10 cm divided by 2.54 is about 3.94 inches.
How do I convert inches to centimetres?
Multiply inches by 2.54. For example, 12 inches multiplied by 2.54 is 30.48 cm.
How many kilometres are in a mile?
One mile is 1.609344 kilometres. For everyday use, 1 mile is often rounded to about 1.61 km.
Should I round length conversions?
Yes, but round based on the use case. Keep more decimals for precise work and fewer decimals for everyday estimates.