Length converter
This length converter turns millimetres, centimetres, metres and kilometres into inches, feet, yards and miles. Type a value, choose the unit you start from, and every other unit updates instantly.
It covers the conversions people look up most: cm to inches, mm to inches, inches to cm, meters to feet and kilometers to miles.
Result
3.937 inch
Formula: 10 centimetre × 0.393700787402 ≈ 3.93700787402 inch
In every unit
| Unit | Value |
|---|---|
| millimetre | 100 |
| centimetre | 10 |
| metre | 0.1 |
| kilometre | 0.0001 |
| inch | 3.937 |
| foot | 0.328084 |
| yard | 0.109361 |
| mile | 0.000062137 |
| nautical mile | 0.000053996 |
Metric units of length
The metric system is built on the metre, and each step is a power of ten, so converting is a matter of moving the decimal point.
| Unit | In metres | Plain equivalent |
|---|---|---|
| 1 millimetre | 0.001 | 1 m = 1,000 mm |
| 1 centimetre | 0.01 | 1 m = 100 cm |
| 1 decimetre | 0.1 | 1 m = 10 dm |
| 1 metre | 1 | base unit |
| 1 kilometre | 1,000 | 1 km = 100,000 cm |
Inches, feet and miles
Imperial units are tied to the metre by the 1959 international agreement, so these conversions are exact rather than approximate.
| Unit | In metres | Metric equivalent |
|---|---|---|
| 1 inch | 0.0254 | exactly 2.54 cm |
| 1 foot | 0.3048 | 30.48 cm = 12 inches |
| 1 yard | 0.9144 | 91.44 cm = 3 feet |
| 1 mile | 1,609.344 | 1.609 km = 1,760 yards |
| 1 nautical mile | 1,852 | 1.852 km |
Converting length by hand
- Centimetres to inches: divide by 2.54. 90 cm ÷ 2.54 ≈ 35.43 in.
- Inches to centimetres: multiply by 2.54. 32 in × 2.54 = 81.28 cm.
- Millimetres to inches: divide by 25.4. 200 mm ÷ 25.4 ≈ 7.87 in.
- Metres to feet: multiply by 3.28084. 1.8 m × 3.28084 ≈ 5.91 ft.
- Kilometres to miles: divide by 1.609344. 10 km ÷ 1.609344 ≈ 6.21 mi.
Quick reference
| Conversion | Result |
|---|---|
| 1 inch in millimetres | 25.4 mm |
| 10 cm in inches | 3.937 in |
| 30 cm in inches | 11.811 in |
| 1 metre in feet | 3.281 ft |
| 5 km in miles | ≈ 3.107 mi |
| 1 mile in kilometres | 1.609 km |
Frequently asked questions
How many centimeters are in an inch?
One inch is exactly 2.54 centimetres — a defined value, not a rounded one.
How do I convert cm to inches?
Divide the number of centimetres by 2.54. For example, 175 cm ÷ 2.54 ≈ 68.9 inches.
How many millimeters are in an inch?
An inch holds 25.4 millimetres.
How many feet are in a meter?
One metre equals about 3.28084 feet, which is 3 feet 3.37 inches.
How many kilometers are in a mile?
A land mile is 1.609344 km. A nautical mile is longer at 1.852 km.
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Updated: 2026-08-09