Convert inches to centimetres and back in one tap. Useful for screen sizes, furniture measurements and sewing patterns – one inch is exactly 2.54 centimetres.
Inches ⇄ Centimetres Converter
Read the full method in our guide: How to Convert Inches to Centimetres
How to use the Inches to Centimetres Converter
- Type the length in inches into the box.
- The answer in centimetres appears below straight away.
- Need the reverse? The tool works both ways — enter centimetres and it gives you inches.
- A short formula line is shown with each result, so you can repeat the sum on paper if you need to.
The formula
One inch is exactly 2.54 centimetres — not roughly, exactly. It has been the fixed international definition since 1959, so the maths is simple: centimetres = inches × 2.54.
The inches figure is your input and the centimetres figure is the result. Going the other way, divide centimetres by 2.54 to get inches. Twelve inches make one foot, which is why screen sizes, photo frames and many tools are still sold in inches even in countries that measure everything else in centimetres.
Quick conversion table
| Inches | Centimetres |
|---|---|
| 1 in | 2.54 cm |
| 2 in | 5.08 cm |
| 5 in | 12.7 cm |
| 10 in | 25.4 cm |
| 12 in | 30.48 cm |
| 24 in | 60.96 cm |
| 36 in | 91.44 cm |
Worked example
A laptop is advertised as having a 10-inch-wide accessory sleeve, and the shelf you want to store it on is measured in centimetres. Multiply 10 by 2.54 and you get 25.4 cm — so a shelf space a little over 26 cm deep will hold it comfortably. The same sum works for a TV: a 55-inch screen is measured corner to corner, and 55 × 2.54 = 139.7 cm tells you the diagonal, though the actual width of the set is less than that because the diagonal is the longest line across it.
Common mistakes
- Using 2.5 as the conversion. Handy for a rough guess, but over 36 inches the error grows to more than a centimetre — too much for furniture or frames.
- Measuring a screen by its width. Screen inches are corner to corner, diagonally. A “24-inch” monitor is not 24 inches wide.
- Rounding halfway through. Keep the full number until the end, then round once. Rounding at each step stacks up small errors.
- Reading a tape measure’s small marks as centimetres. On dual-scale tapes the inch side is usually on top; check which edge you are reading before you cut anything.
Frequently asked questions
Q: How many centimetres are in a foot?
One foot is 12 inches, and 12 × 2.54 = 30.48 cm.
Q: How do I turn centimetres back into inches?
Divide by 2.54. A 100 cm curtain rail, for example, is 100 ÷ 2.54 = about 39.37 inches.
Q: Is the result exact or rounded?
The conversion itself is exact, because 1 inch is defined as exactly 2.54 cm. The converter may show the answer rounded to two decimal places, which is closer than any tape measure can read.