How many centimetres are in an inch?

Exactly 2.54. The inch has been defined as precisely 25.4 millimetres by international agreement since 1959, so this is a definition rather than a measurement and the conversion carries no error.

Why is a nautical mile different from a mile?

A nautical mile is 1,852 metres, chosen to approximate one minute of latitude, which makes chart work straightforward. A statute mile is 1,609.344 metres and has no such relationship to the globe.

How do I convert feet and inches to metres?

Convert the whole thing to inches first — multiply feet by 12 and add the inches — then multiply by 0.0254. Six foot two is 74 inches, or 1.8796 metres.

Is a US inch the same as a UK inch?

Yes, since 1959, when both adopted the international inch of exactly 25.4 millimetres. Before that they differed by a few millionths, which mattered only in precision engineering.

What is the difference between a yard and a metre?

A yard is 0.9144 metres, so a metre is about 9 percent longer. The two are close enough that they are often confused and far enough apart to matter over any distance.

Length Converter

Convert metres, feet, inches, miles, yards and more — instantly, in your browser.

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About the Length Converter

Convert between metres, feet, inches, miles and eight more in one place. Values update as you type, and the result is calculated by converting to a base unit and back — so the arithmetic is the same in both directions and round-tripping a number returns exactly what you started with.

The awkward ones are all defined exactly rather than measured. An inch is precisely 25.4 millimetres by international agreement since 1959, a foot is 0.3048 metres and a mile is 1,609.344 metres — so these conversions are exact, not approximations, and any rounding you see is display precision only.

The nautical mile is the odd one out: 1,852 metres exactly, chosen because it is close to one minute of latitude, which is what makes it useful for navigation and useless for anything else.

How it works

Type a value and choose the units to convert between.
The result updates as you type, with the same value shown in every other unit below.
Jump straight to a direct page for the common conversions listed at the bottom.

Frequently asked questions

How many centimetres are in an inch?: Exactly 2.54. The inch has been defined as precisely 25.4 millimetres by international agreement since 1959, so this is a definition rather than a measurement and the conversion carries no error.
Why is a nautical mile different from a mile?: A nautical mile is 1,852 metres, chosen to approximate one minute of latitude, which makes chart work straightforward. A statute mile is 1,609.344 metres and has no such relationship to the globe.
How do I convert feet and inches to metres?: Convert the whole thing to inches first — multiply feet by 12 and add the inches — then multiply by 0.0254. Six foot two is 74 inches, or 1.8796 metres.
Is a US inch the same as a UK inch?: Yes, since 1959, when both adopted the international inch of exactly 25.4 millimetres. Before that they differed by a few millionths, which mattered only in precision engineering.
What is the difference between a yard and a metre?: A yard is 0.9144 metres, so a metre is about 9 percent longer. The two are close enough that they are often confused and far enough apart to matter over any distance.

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