Inches to centimetres – and centimetres to inches
1 in = 2.54 cm
All units in this category
- 25.4mm
- 2.54cm
- 0.0254m
- 0.0000254km
- 0.00000254mil
- 1in
- 0.083333333ft
- 0.027777778yd
- 0.000015782828mi
- 0.000013714903M
Formula
Multiply the value in inches by 2.54 to get centimetres.cm = in × 2.54
Multiply the value in centimetres by 0.39370079 to get inches.in = cm × 0.39370079
How to convert inches to centimetres
Type a value in the field above and the result is calculated instantly. Use the arrow button to swap direction, or pick other units from the lists.
Doing it in your head
A rough conversion for when the calculator is not to hand. The error comes last, and it holds in both directions at that order of magnitude.
- Inches to centimetres: × 3 − 15%. That gives 2.55 instead of 2.54, an error of 0.39%.
- Centimetres to inches: × 3 ÷ 8 + 5%. That gives 0.3938 instead of 0.393701, an error of 0.01%.
Inches to centimetres – common values
| Inches (in) | Centimetres (cm) |
|---|---|
| 1 | 2.54 |
| 2 | 5.08 |
| 3 | 7.62 |
| 5 | 12.7 |
| 10 | 25.4 |
| 20 | 50.8 |
| 50 | 127 |
| 100 | 254 |
| 500 | 1,270 |
| 1,000 | 2,540 |
Centimetres to inches – common values
| Centimetres (cm) | Inches (in) |
|---|---|
| 1 | 0.393701 |
| 2 | 0.787402 |
| 3 | 1.1811 |
| 5 | 1.9685 |
| 10 | 3.93701 |
| 20 | 7.87402 |
| 50 | 19.685 |
| 100 | 39.3701 |
| 500 | 196.85 |
| 1,000 | 393.701 |
About the units
Inches. An inch is one thirty-sixth of a yard, which has made it exactly 2.54 centimetres since the international yard and pound agreement of 1959. It is used worldwide for screen diagonals, pipe and screw sizes and tyre and wheel dimensions, and as a general length in the US. Within the EU it may appear only as a supplementary indication beside the metric figure. Inches are written as fractions in trade, 3/8 in, but as decimals in engineering. The symbol ″ also means an arcsecond.
Centimetres. A centimetre is one hundredth of a metre, since the SI prefix centi means 10⁻². As a decimal submultiple of the metre it is a legal unit throughout the EU, and it is the everyday measure for height, clothing sizes and furniture in metric countries. It also appears on US packaging beside the inch figure. An inch is 2.54 centimetres, so a six-inch screen measures just over 15 centimetres diagonally. In the old CGS system the centimetre was a base unit. Write cm, never “cms”.