How many inches is one centimetre?

One centimetre is 1/2.54 inches, about 0.3937 inches. Going the other way, one inch is exactly 2.54 centimetres — a value fixed by international agreement in 1959, not a measurement.

What does a screen's inch measurement refer to?

The diagonal, not the width or height. A 27-inch screen has a 68.58 cm diagonal; the actual width and height depend on the aspect ratio, and a 16:9 27-inch panel is roughly 59.8 cm wide and 33.6 cm tall.

UNIT CONVERSION · CALCULATED FROM DEFINITIONS

Centimetres to Inches Converter

Convert cm and inches both ways, with a common-size table and the exact definition.

From

Formulain = cm × 0.393700787

Ratio1 cm = 0.393700787 in

Every unit in this category

m0.01Metre

km0.00001Kilometre

mm10Millimetre

µm10,000Micrometre

in0.393700787Inch

ft0.032808399Foot

yd0.010936133Yard

mi0.000006214Mile

nmi0.0000054Nautical mile

台尺0.033Taiwanese foot

Common values

cm	in
`0.5 cm`	`0.196850394 in`
`1 cm`	`0.393700787 in`
`2 cm`	`0.787401575 in`
`3 cm`	`1.181102 in`
`5 cm`	`1.968504 in`
`10 cm`	`3.937008 in`
`15 cm`	`5.905512 in`
`20 cm`	`7.874016 in`
`25 cm`	`9.84252 in`
`30 cm`	`11.811024 in`
`50 cm`	`19.685039 in`
`75 cm`	`29.527559 in`
`100 cm`	`39.370079 in`
`150 cm`	`59.055118 in`
`200 cm`	`78.740157 in`
`500 cm`	`196.8504 in`
`1000 cm`	`393.7008 in`

About this tool

Enter centimetres to get inches; the two fields are linked so editing either updates the other, and the swap control reverses the direction. An inch is defined internationally as exactly 2.54 cm, so there is no approximation in this conversion. The table below covers the sizes that come up when buying screens, wheels, clothing, and furniture.

How it works

Enter a value in centimetres, or type directly into the inches field.
Use the swap control to reverse the direction.
Read a common size from the table, or copy a single result.

Precision and definitions

One inch is defined as exactly 0.0254 metres — a definition, not a measured approximation.

Privacy

Every conversion runs inside this browser. The values you enter are never uploaded, stored, or written to the URL or any log.

Frequently asked questions

How many inches is one centimetre?: One centimetre is 1/2.54 inches, about 0.3937 inches. Going the other way, one inch is exactly 2.54 centimetres — a value fixed by international agreement in 1959, not a measurement.
What does a screen's inch measurement refer to?: The diagonal, not the width or height. A 27-inch screen has a 68.58 cm diagonal; the actual width and height depend on the aspect ratio, and a 16:9 27-inch panel is roughly 59.8 cm wide and 33.6 cm tall.

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