Length Converter
Last updated: 2026-06-25
Length conversion uses international factors — 1 inch = 2.54 cm, 1 foot = 30.48 cm, 1 yard = 91.44 cm, 1 mile = 1,609.344 m — by converting every unit to meters first and then to the unit you want.
Enter a value below and pick a unit; mm, cm, m, km, inches, feet, yards and miles update instantly.
Enter a length
Results (all units)
| Unit | Value |
|---|
How to use
- Enter a value — Type the length value you want to convert.
- Pick the source unit — Choose the unit of your value (for example cm or inches) from the dropdown.
- Read the results — mm, cm, m, km, inches, feet, yards and miles all update instantly in the table.
Length conversion factors and cm to inches
The key to length conversion is collecting every unit into a single base unit (here, the meter) and then dividing back into the unit you want. The metric units (mm, cm, m, km) are linked by powers of ten, while the imperial units (inch, foot, yard, mile) all derive from the definition 1 inch = 2.54 cm.
| Unit | In meters | Note |
|---|---|---|
| Millimeter (mm) | 0.001 m | 1 cm = 10 mm |
| Centimeter (cm) | 0.01 m | 1 m = 100 cm |
| Meter (m) | 1 m | base unit |
| Kilometer (km) | 1,000 m | 1 km = 1,000 m |
| Inch (in) | 0.0254 m | 1 in = 2.54 cm |
| Foot (ft) | 0.3048 m | 1 ft = 12 in = 30.48 cm |
| Yard (yd) | 0.9144 m | 1 yd = 3 ft = 91.44 cm |
| Mile (mi) | 1,609.344 m | 1 mi = 1,760 yd |
For example, to turn a height of 170 cm into inches, divide 170 by 2.54 to get about 66.93 inches, which is roughly 5 feet 6.9 inches. For more conversion tips, see the unit conversion cheat sheet.
Frequently asked questions (FAQ)
How many cm is 1 inch?
One inch is exactly 2.54 cm. The inch is defined as 2.54 centimeters in the international yard and pound system, so to convert inches to cm multiply by 2.54. To convert cm back to inches, divide by 2.54.
How many cm and inches is 1 foot?
One foot is 12 inches, which equals 30.48 cm. One yard is 3 feet (36 inches) or 91.44 cm, and one mile is 1,609.344 m.
How tall is 170 cm in feet and inches?
170 cm is about 5.577 feet, which reads as roughly 5 feet 6.9 inches. Dividing 170 by 2.54 gives about 66.93 inches, and dividing that by 12 gives 5 feet with about 6.93 inches left over.
Why is the result slightly different from other tools?
This converter uses international factors such as 1 inch = 2.54 cm, but only displays a limited number of decimal places after rounding. So the last digit may differ from tools that round differently.
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Last updated: 2026-06-25