Length Converter

Use this free length converter to change a length between nanometres, micrometres, millimeters, centimeters, decimeters, meters, kilometers, mils, inches, feet, yards, miles, nautical miles and fathoms. Type a number in either box and the other one follows as you type, with the same length in the main units shown underneath. You can type feet and inches (5'8 or 5 ft 8 in) or a fraction (5/16 or 1 1/2), and get a height such as 5 ft 10.87 in. Pick how many decimals to round to, swap the two units with one click, and copy a link to your conversion. Charts list the most searched values for cm to inches, mm to inches, meters to feet and miles to km, plus heights, inch fractions in millimeters, how many feet are in a mile, and running distances. It is free and instant, and your numbers stay in your browser.

How to convert centimeters to inches

Divide the centimeters by 2.54. An inch is defined as exactly 2.54 centimeters, so the answer is exact.

For 20 cm: 20 ÷ 2.54 = 7.874 in. For 180 cm: 180 ÷ 2.54 = 70.866142 in.

How to convert inches to centimeters

Multiply the inches by 2.54: cm = inches × 2.54. For 5 in: 5 × 2.54 = 12.7 cm. For 12 in, which is one foot: 12 × 2.54 = 30.48 cm.

Feet and inches (height)

To change centimeters to feet and inches, turn them into inches first, then divide by 12. The whole part is the feet and the rest is the inches. For 180 cm: 180 ÷ 2.54 = 70.87 in, and 70.87 ÷ 12 = 5 feet with 10.87 inches left over, so 180 cm is 5 ft 10.87 in. Going back, 5 ft 8 in is 5 × 12 + 8 = 68 in, and 68 × 2.54 = 172.72 cm. You can type a height as 5'8, 5 ft 8 in or 5-8, and choose "Feet and inches" in either list to see the answer that way.

Meters and feet

A foot is exactly 0.3048 meters. To change meters to feet, divide by 0.3048 (or multiply by 3.28084): 2 m is 6.56168 ft. To change feet to meters, multiply by 0.3048: 10 ft is 3.048 m.

Kilometers and miles

A mile is exactly 1.609344 kilometers. Multiply miles by 1.609344 to get kilometers, or divide kilometers by 1.609344 to get miles: 10 km is 6.213712 mi, and 5 mi is 8.04672 km.

Millimeters, inches and fractions of an inch

An inch is 25.4 millimeters, so divide millimeters by 25.4 to get inches: 10 mm is 0.393701 in. For a fraction of an inch, multiply it by 25.4: 5/16 in is 0.3125 × 25.4 = 7.9375 mm, and 1/2 in is 12.7 mm. You can type fractions such as 5/16 or 1 1/2 straight into the box.

How many feet are in a mile?

A mile is 5,280 feet, which is 1,760 yards or 1,609.344 meters. A yard is 3 feet or 36 inches, and a foot is 12 inches. The "How Many in a …?" table above lists these and more.

Metric and imperial units

The metric system is built on the meter, and every other metric unit is a power of ten of it: a millimeter is a thousandth of a meter, a centimeter a hundredth and a kilometer a thousand meters. The imperial and US customary units (inch, foot, yard, mile) are used for everyday lengths in the United States. They are all defined in terms of the meter today, which is why the conversions are exact.

The nautical mile, the fathom and the mil

A nautical mile is exactly 1,852 meters, which is 1.852 km or about 1.150779 miles. It is used at sea and in the air. A fathom is 6 feet (1.8288 m) and is used for the depth of water. A mil, or thou, is one thousandth of an inch (0.0254 mm), used for the thickness of films and coatings.

Running distances

Track distances are given in meters. A 400 m lap is 0.248548 miles (1,312.34 feet), 1,500 m is 0.932057 miles and 5,000 m is 3.106856 miles. The running table above lists the common ones.