Length & Distance Converter
Instantly convert millimeters, centimeters, meters, kilometers, inches, feet, yards, miles and more. Free, fast online length converter.
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All units
| Unit | Value | Copy |
|---|---|---|
| Nanometernm | 254000000 | |
| Micrometerµm | 254000 | |
| Millimetermm | 254 | |
| Centimetercm | 25.4 | |
| Meterm | 0.254 | |
| Kilometerkm | 0.000254 | |
| Inchin | 10 | |
| Footft | 0.83333333 | |
| Yardyd | 0.27777778 | |
| Milemi | 0.00015782828 | |
| Nautical Milenmi | 0.00013714903 | |
| Light-yearly | 2.684706e-17 |
Popular conversions
How length conversion works
Each unit is stored as a number of meters. Since the 1959 international yard and pound agreement, the inch is exactly 2.54 cm, so every imperial length is an exact decimal of a meter: the foot is 0.3048 m, the yard 0.9144 m and the international mile 1,609.344 m. Metric units differ by powers of ten, so moving between mm, cm, m and km only shifts the decimal point.
The converter multiplies your number by the source unit's length in meters and divides by the target unit's. The nautical mile (1,852 m, used at sea and in aviation) and the light-year are included for completeness. The light-year is a distance, not a time.
Worked examples
Height, feet and inches to centimeters
5 ft 10 in is 5 × 12 + 10 = 70 inches. 70 × 2.54 = 177.8 cm. Converting the feet and the inches separately and then adding gives the same answer; typing 5.10 ft does not, because 10 inches is 0.833 ft.
Running distances
A 5 km race is 5,000 ÷ 1,609.344 = 3.11 miles. A marathon is 42.195 km, which is 26.22 miles.
Drill bits and hardware
A 3/8-inch bit is 0.375 × 25.4 = 9.525 mm, so a 9.5 mm metric bit is the nearest match. 10 mm is 0.394 in, a little over 3/8.
Common lengths in metric and imperial
| m | cm | in | ft | yd | |
|---|---|---|---|---|---|
| 1 centimeter | 0.01 | 1 | 0.393701 | 0.0328084 | 0.0109361 |
| Credit card width (ISO ID-1, 85.6 mm) | 0.0856 | 8.56 | 3.37008 | 0.28084 | 0.0936133 |
| 1 foot | 0.3048 | 30.48 | 12 | 1 | 0.333333 |
| 1 meter | 1 | 100 | 39.3701 | 3.28084 | 1.09361 |
| Standard interior door height (80 in) | 2.032 | 203.2 | 80 | 6.66667 | 2.22222 |
| Tennis court length (78 ft) | 23.7744 | 2,377.44 | 936 | 78 | 26 |
| 100 meters | 100 | 10,000 | 3,937.01 | 328.084 | 109.361 |
Common mistakes
- Treating feet-and-inches as a decimal. 5'6" is 5.5 ft, not 5.6 ft. Convert to inches first (66 in), then to cm (167.64 cm).
- Converting area with a length factor. 1 ft is 0.3048 m, but 1 sq ft is 0.0929 m² (0.3048 squared). Use the area converter for square units.
- Mixing statute and nautical miles. A nautical mile is 1,852 m, about 1.151 statute miles. Marine and aviation charts use nautical miles.
- Using the old US survey foot. It was retired at the end of 2022; everyday and engineering work uses the international foot of exactly 0.3048 m (NIST).
Sources
Conversion charts
- Centimeters to Inches (cm to in)
- Inches to Centimeters (in to cm)
- Feet to Meters (ft to m)
- Meters to Feet (m to ft)
- Kilometers to Miles (km to mi)
- Miles to Kilometers (mi to km)
- Millimeters to Inches (mm to in)
- Inches to Millimeters (in to mm)
- Inches to Feet (in to ft)
- Feet to Inches (ft to in)
- Centimeters to Feet (cm to ft)
- Feet to Yards (ft to yd)
- Yards to Feet (yd to ft)
- Meters to Yards (m to yd)
Frequently asked questions
How many centimeters are in an inch?
1 inch equals exactly 2.54 centimeters.
How do I convert meters to feet?
Multiply meters by 3.28084 to get feet.
How many inches are in a meter?
39.3701 inches, because 1 m ÷ 0.0254 m = 39.37.
How many feet are in a mile?
5,280 feet, exactly 1,609.344 meters.
How do I convert cm to feet and inches?
Divide cm by 2.54 to get inches, then divide by 12: the whole number is feet and the remainder is inches. 180 cm = 70.87 in = 5 ft 10.9 in.