Last updated: September 2026
Length conversion
Inches to Centimeters (in to cm)
Convert screen sizes, product dimensions, clothing measurements, and workshop plans from inches to centimeters.
1 in
2.54 cm
cm = in × 2.54
The formula
How to convert inches to centimeters
Apply cm = in × 2.54. For example, 1 in equals 2.54 cm.
Precision
Accurate constants, readable results
OmniUnit calculates with the full stored conversion factor, then displays up to 12 significant digits.
Common inches conversions
| Inches | Centimeters |
|---|---|
| 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 |
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Frequently asked questions
How many centimeters are in 1 inch?
One inch equals exactly 2.54 centimeters, by international definition. The inch has been defined as exactly 2.54 centimeters since 1959, so this conversion is exact — not an approximation.
How many inches are in 1 centimeter?
One centimeter equals 0.393700787402 inches. To convert centimeters back to inches, use the centimeters-to-inches page, which shows the exact formula and a quick calculator.
How do I convert inches to centimeters without a calculator?
Multiply the inches by 2.5 for a quick estimate — for example, 20 inches is about 50 centimeters. For precise results, use the calculator above or multiply the inches by 2.54.
Is the inch-to-centimeter conversion exact?
Yes. The inch is defined as exactly 2.54 centimeters, so this conversion is a fixed definition, not a measurement. OmniUnit calculates with the full stored factor for maximum precision.