Inches to cm
One in equals 2.54 cm. Type any number and the answer appears as you type — the maths happens in your browser.
Result
The same value in every unit
| Unit | Value |
|---|
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Common values
| inches | cm |
|---|---|
| 1 in | 2.54 cm |
| 2 in | 5.08 cm |
| 3 in | 7.62 cm |
| 5 in | 12.7 cm |
| 10 in | 25.4 cm |
| 15 in | 38.1 cm |
| 20 in | 50.8 cm |
| 25 in | 63.5 cm |
| 50 in | 127 cm |
| 100 in | 254 cm |
| 500 in | 1270 cm |
| 1000 in | 2540 cm |
How to use
- Enter the number of inches in the field.
- The result in cm updates on every keystroke.
- Use the table below for the values people look up most often.
Formula and reverse conversion
The formula
To convert by hand: cm = in × 2.54. Going back the other way, one cm is 0.3937007874 in.
Where the odd number comes from
The factor is not a round number because the imperial units are defined through the metric ones by international agreement: an inch is exactly 25.4 mm and a pound is exactly 0.45359237 kg. Everything else follows from those definitions.
cm = in × 2.54
Frequently asked questions
How many cm are in one inches?
One in is 2.54 cm.
How do I convert inches to cm?
Multiply by the factor: cm = in × 2.54.
Is the result exact?
The factors are the exact legal definitions, and up to ten significant digits are kept in the answer. Rounding happens only in the display.
How do I convert cm back to inches?
One cm is 0.3937007874 in — or open the reverse page linked below.