📏 Length Converter
Convert centimeters, inches, feet, meters and miles — every length unit at once.
Common length conversions
| Value | cm | m | in | ft | Note |
|---|---|---|---|---|---|
| 1 in | 2.54 | 0.0254 | 1 | 0.0833333 | definition of the inch |
| 1 ft | 30.48 | 0.3048 | 12 | 1 | 12 inches |
| 1 yd | 91.44 | 0.9144 | 36 | 3 | football / golf distances |
| 1 m | 100 | 1 | 39.3701 | 3.28084 | |
| 100 m | 10,000 | 100 | 3,937.01 | 328.084 | track sprint |
| 1 km | 100,000 | 1,000 | 39,370.1 | 3,280.84 | |
| 1 mi | 160,934 | 1,609.34 | 63,360 | 5,280 | 5,280 feet |
| 1 NM | 185,200 | 1,852 | 72,913.4 | 6,076.12 | sea and air navigation |
| 5 km | 500,000 | 5,000 | 196,850 | 16,404.2 | 5K run |
| 26.2188 mi | 4,219,507 | 42,195.1 | 1,661,223 | 138,435 | marathon (42.195 km) |
| 29,032 ft | 884,895 | 8,848.95 | 348,384 | 29,032 | Mount Everest |
How to use the length converter
Enter a value and choose the unit you have. It is converted into metric, US customary and other units at the same time. The unit you pick under "To" is shown as the big number, and ⇄ swaps the direction. If you only ever go one way, the dedicated cm to inches and inches to cm pages are faster and include charts.
Length units at a glance
| Unit | Symbol | Definition |
|---|---|---|
| Millimeter | mm | 1/1,000 of a meter |
| Centimeter | cm | 1/100 of a meter |
| Meter | m | SI base unit |
| Kilometer | km | 1,000 m |
| Inch | in | Exactly 2.54 cm (1959 international agreement) |
| Foot | ft | 12 inches = 30.48 cm |
| Yard | yd | 3 feet = 91.44 cm |
| Mile | mi | 1,760 yards ≈ 1.609 km |
| Nautical mile | NM | 1,852 m, used at sea and in aviation |
| Ja (Korean foot) | ja | Traditional Korean unit, 10/33 m ≈ 30.3 cm |
| Chi (Korean inch) | chi | 1/10 ja ≈ 3.03 cm |
| Kan (Korean bay) | kan | 6 ja ≈ 1.82 m |
| Ri (Korean li) | ri | 1,296 ja ≈ 392.7 m (10 ri ≈ 4 km) |
How to convert length
Every unit is converted to meters first, then to the target unit: result = value × (meters per from-unit) ÷ (meters per to-unit). For example, 6 feet to centimeters is 6 × 0.3048 ÷ 0.01 = 182.88 cm.
inches = cm ÷ 2.54cm = inches × 2.54feet = meters × 3.28084meters = feet × 0.3048miles = km × 0.621371km = miles × 1.609344
Inches, feet, yards and miles have been defined in terms of the meter since the 1959 international yard and pound agreement (1 in = 2.54 cm exactly), so these conversions are exact. The traditional Korean units at the bottom of the list use the modern standard of 1 ja = 10/33 m; historic values varied by period and region.
Height in feet and inches
A height of 5′9″ means 5 feet 9 inches. In centimeters that is 5 × 30.48 + 9 × 2.54 = 175.26 cm. Going the other way, 170 cm = 66.9 inches = 5 feet 6.9 inches, which people round to "5 foot 7". The cm to inches page shows the feet-and-inches split automatically.
Miles vs. nautical miles
A statute mile (1,609 m) and a nautical mile (1,852 m) are different units. A nautical mile is one minute of latitude, which is why ships and aircraft use it — and a knot is one nautical mile per hour.
Quick mental math
A meter is a little over a yard (39.4 inches). A kilometer is about 0.6 miles, so a 5K is 3.1 miles and a 10K is 6.2 miles. A foot is about 30 cm, and an inch is about 2.5 cm.
Results are rounded to at most 7 significant digits. Traditional Korean units are shown for reference.