Conversion factor
1 in = 2.54 cm
and 1 cm = 0.393701 in
The formula
centimetres = inches × 2.54
Worked example. To convert 2 in, multiply by 2.54: 2 × 2.54 = 5.08 cm.
Inches to Centimetres conversion table
| inches (in) | centimetres (cm) |
|---|---|
| 1 | 2.54 |
| 2 | 5.08 |
| 5 | 12.7 |
| 10 | 25.4 |
| 12 | 30.48 |
| 24 | 60.96 |
| 36 | 91.44 |
| 48 | 121.92 |
| 72 | 182.88 |
About inches and centimetres
One inch is defined as exactly 2.54 centimetres. This is not a measured approximation but a definition, fixed by the 1959 international yard and pound agreement. Every other imperial length follows from it: a foot is 12 inches or 30.48 cm, a yard is 36 inches or 91.44 cm.
Because the factor is exact and small, the conversion is unusually easy to do by hand. Multiplying by 2.5 gets you within two percent, which is close enough for most practical purposes, and the exact figure only adds a further 1.6%.
Inches persist in some specific places even in metric countries: screen diagonals, pipe and fastener sizes, wheel diameters, and print resolution in dots per inch. A 27-inch monitor is 68.58 cm corner to corner, and A4 paper at 21 × 29.7 cm is 8.27 × 11.69 inches, which is why it never quite matches US Letter.
Need other units?
The full unit converter handles every unit in this family.
Open the Unit ConverterQuestions
Frequently Asked Questions
- How many centimetres are in an inch?
- Exactly 2.54 centimetres. This is a definition rather than a measurement, agreed internationally in 1959, so there is no rounding involved.
- How do I convert inches to centimetres?
- Multiply the number of inches by 2.54. A 10 inch length is 10 × 2.54 = 25.4 cm. Going the other way, divide centimetres by 2.54.
- What is 5 foot 10 in centimetres?
- 5 foot 10 is 70 inches, which is 177.8 cm. Convert feet to inches first by multiplying by 12, add the remaining inches, then multiply the total by 2.54.
- How big is a 27 inch monitor in centimetres?
- 68.58 cm measured diagonally, since screen sizes always quote the diagonal rather than the width. The actual width depends on the aspect ratio.
Keep going