Length Converter

Every unit of distance, in one place.

Convert between millimeters, centimeters, meters, kilometers, inches, feet, yards and miles — instantly, no sign-up.

How it works

Every value is converted to meters first, then to the target unit, using exact international definitions (for example, 1 inch = 2.54 cm and 1 mile = 1,609.344 m).

When it helps

Handy for DIY measurements, travel distances, product dimensions, or homework that switches between metric and imperial units.

Metric and imperial at a glance

The metric system scales by tens: 10 millimeters make a centimeter, 100 centimeters a meter, and 1,000 meters a kilometer. Imperial units don't follow one pattern: 12 inches make a foot, 3 feet a yard, and 1,760 yards a mile. That's why a converter saves time — moving between the two systems almost always involves awkward factors.

Since 1959 the inch has been defined as exactly 2.54 cm, so every imperial length has an exact metric equivalent. This converter uses those exact definitions, and rounding only happens when the result is displayed.

Worked example

Say a TV is listed as 55 inches across the diagonal. 55 × 2.54 = 139.7 cm. A running route of 5 kilometers is 5,000 m ÷ 1,609.344 ≈ 3.11 miles. A person 5 feet 9 inches tall is 69 inches, or 69 × 2.54 = 175.26 cm.

Useful approximations for quick mental math: a meter is a little more than a yard (about 1.09 yd), a kilometer is roughly 0.62 miles, and 30 cm is close to one foot.

Frequently asked questions

How many centimeters are in a foot?

Exactly 30.48 cm.

Is a nautical mile included?

This converter covers everyday land units; nautical miles appear in the Speed Converter via knots.

How do I convert feet and inches together?

Convert the feet to inches first (feet × 12), add the inches, then convert the total. For example 5 ft 9 in = 69 in = 175.26 cm.

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