Metric and imperial length units
The metric system builds every length on the meter: a millimeter is a thousandth of it, a centimeter a hundredth, a kilometer a thousand meters. The imperial and US customary system uses the inch, foot, yard and mile, which have been tied to the metric system since 1959: one inch is exactly 2.54 centimeters.
- 1 foot is 12 inches, or exactly 30.48 cm.
- 1 yard is 3 feet, or exactly 0.9144 m.
- 1 mile is 1,760 yards or 5,280 feet, or exactly 1.609344 km.
- 1 nautical mile is exactly 1,852 m. It is used at sea and in aviation.
Common length conversions
| From | Equals |
|---|---|
| 1 inch | 2.54 centimeters |
| 1 centimeter | 0.3937007874 inches |
| 1 foot | 0.3048 meters |
| 1 meter | 3.280839895 feet |
| 1 yard | 0.9144 meters |
| 1 mile | 1.609344 kilometers |
| 1 kilometer | 0.6213711922 miles |
| 1 nautical mile | 1.852 kilometers |
Centimeters to inches chart
| Centimeters (cm) | Inches (in) |
|---|---|
| 1 | 0.3937 |
| 2 | 0.7874 |
| 3 | 1.1811 |
| 5 | 1.9685 |
| 10 | 3.937 |
| 15 | 5.9055 |
| 20 | 7.874 |
| 25 | 9.8425 |
| 30 | 11.811 |
| 50 | 19.685 |
| 100 | 39.37 |
Feet to meters chart
| Feet (ft) | Meters (m) |
|---|---|
| 1 | 0.3048 |
| 2 | 0.6096 |
| 3 | 0.9144 |
| 4 | 1.2192 |
| 5 | 1.524 |
| 6 | 1.8288 |
| 7 | 2.1336 |
| 8 | 2.4384 |
| 10 | 3.048 |
| 20 | 6.096 |
| 50 | 15.24 |
| 100 | 30.48 |
Where the conversions come up
Height is the classic one. Someone tells you they are 5 ft 11 and you want that in centimeters: 5 × 30.48 plus 11 × 2.54 gives 180.3 cm. Screen sizes and tire diameters are quoted in inches almost everywhere, running distances in kilometers in one country and miles in the next, and furniture from an American shop arrives with measurements that make no sense next to a European tape measure. Each of those is a two-second job here.
A few shortcuts for when you have no converter at hand: inches to centimeters is roughly times 2.5, miles to kilometers is times 1.6, and meters to feet is times 3.3. For feet to meters, take 30 percent. These get you within a few percent, which is fine for a conversation and not fine for a cut list.
How to use it
- 1Choose the unit you are starting from on the left, for example centimeters, and the unit you need on the right.
- 2Type the value. You can type on either side, so going back from inches to centimeters is the same box, and the swap button flips the pair.
- 3Below the result you see the exact factor and your value in every other length unit, from millimeters to nautical miles. Tap one to make it the target, or copy the result or a link.
Frequently asked questions
How many centimeters are in an inch?
Exactly 2.54. The inch was defined this way in 1959, so the conversion is not an approximation: 10 inches are 25.4 cm and 1 cm is about 0.3937 inches.
How do I convert feet and inches to centimeters?
Multiply the feet by 30.48 and the inches by 2.54, then add both. For example, 5 ft 9 in is 152.4 + 22.86 = 175.26 cm.
What is the difference between a mile and a nautical mile?
A mile (statute mile) is 1,609.344 m and is used on roads in the US and UK. A nautical mile is 1,852 m, based on one minute of latitude, and is used at sea and in aviation.
Which foot does the converter use?
The international foot of exactly 0.3048 m. The old US survey foot differed by only two parts per million and was retired at the end of 2022.
How tall is 180 cm in feet and inches?
5 ft 10.9 in, so just under 5 ft 11. Divide by 30.48 to get 5.906 feet, then multiply the 0.906 by 12 to get the inches.