Inches to centimeters
1 inch equals exactly 2.54 cm. Convert inches to centimeters or back, with common sizes and guidance for fractional inches and screen measurements.
Enter your values, then calculate.
Your calculation stays in your browser.
The formula, explained
in × 2.54 = cmThe factor is fixed. Reverse the direction to convert back. Rounding is applied only to the displayed result.
An example to check
Using the starting values below, the calculation gives:
Common conversions
| Inches (in) | Centimeters (cm) |
|---|---|
| 1 | 2.54 |
| 2 | 5.08 |
| 5 | 12.7 |
| 6 | 15.24 |
| 6.5 | 16.51 |
| 10 | 25.4 |
| 12 | 30.48 |
| 18 | 45.72 |
| 20 | 50.8 |
| 25 | 63.5 |
| 28 | 71.12 |
| 30 | 76.2 |
| 36 | 91.44 |
How to use this tool
- Choose “in → cm” to convert inches to centimeters. “in” is the symbol for an inch.
- Enter your length in inches, then calculate. The conversion factor is exact: 1 inch = 2.54 cm. For example, 6 inches × 2.54 = 15.24 cm, and 12 inches × 2.54 = 30.48 cm.
- To convert back, choose “cm → in” and enter a length in centimeters. Divide by 2.54: 27.94 cm ÷ 2.54 = 11 inches.
The table above includes common measurements: 18 inches = 45.72 cm, 20 inches = 50.8 cm, and 30 inches = 76.2 cm. Keep useful decimal places during your calculation and round the final answer to suit your measurement.
How do I enter half an inch or a fraction of an inch?
Convert the fraction to a decimal first. Enter half an inch as 0.5 and a quarter of an inch as 0.25. For 1½ inches, enter 1.5: the result is 3.81 cm. The form accepts decimal numbers, not fraction notation such as 1/2 or 1 1/2.
Does a screen size in inches tell me its width?
A screen’s advertised size usually measures its diagonal, not its width. A 32-inch screen has a diagonal of 81.28 cm. To find the width and height, you also need its aspect ratio, such as 16:9. The outer frame can make the overall dimensions larger.
Is one inch always the same number of pixels?
No. Inches and centimeters measure physical length; the number of pixels depends on the resolution. For an image or print, use the centimeters and pixels converter and enter the PPI.
Conversion reference: NIST — inch-to-centimeter conversion factor ↗.
Can I use a decimal comma?
Yes. Numeric fields accept 12.5 or 12,5 and spaces for thousands, such as 1 234.50. Do not mix a point and comma in one number.
Where are my inputs processed?
Calculations run in your browser. Form values are not sent to Analytics. Copying, printing, sharing or opening an external service is your choice.
Method and interface checked on 2026-10-29 · Report an error