Inches to centimeters converter (in to cm)
in to cm converter
Enter a value on either side to convert.
1 inch is exactly 2.54 centimeters, so 10 inches is 25.4 cm and a 12 inch ruler is 30.48 cm. The definition has been exact since 1959, so the conversion is a fixed multiplication, never an estimate. The converter below works in both directions as you type.
The exact factor from inches to centimeters is 2.54. One inch equals 2.54 centimeters, and the converter uses that full precision internally, rounding only what you see to 4 decimal places.
Worked example: 12 in to cm
To convert 12 inches to centimeters, multiply by the exact factor 2.54:
12 × 2.54 = 30.48
Rounded to 4 decimal places, 12 in is 30.48 cm.
in to cm conversion table
| in | cm |
|---|---|
| 1 | 2.54 |
| 2 | 5.08 |
| 3 | 7.62 |
| 4 | 10.16 |
| 5 | 12.7 |
| 6 | 15.24 |
| 7 | 17.78 |
| 8 | 20.32 |
| 9 | 22.86 |
| 10 | 25.4 |
| 11 | 27.94 |
| 12 | 30.48 |
| 15 | 38.1 |
| 20 | 50.8 |
| 24 | 60.96 |
| 30 | 76.2 |
| 36 | 91.44 |
| 40 | 101.6 |
| 48 | 121.92 |
| 60 | 152.4 |
| 72 | 182.88 |
| 100 | 254 |
Values are rounded to 4 decimal places with trailing zeros trimmed. Need a value that is not listed? Use the converter at the top of the page.
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Frequently asked questions
How many centimeters is 12 inches?
12 inches is 30.48 cm, since 12 inches make 1 foot and 1 foot is exactly 30.48 cm. The arithmetic is 12 × 2.54 = 30.48.
What is the exact conversion factor from inches to centimeters?
1 inch is exactly 2.54 centimeters, a definition in force since 1959. Because it is exact, the 2.54 factor never needs rounding and every conversion starts from full precision.
How wide is a 55 inch TV in centimeters?
A 55 inch screen diagonal is 139.7 cm. TVs and monitors are marketed in inches in the US but often in centimeters elsewhere, so this conversion comes up constantly when comparing models.
How do I convert centimeters back to inches?
Divide the centimeters by 2.54. For example, 50 cm is 19.685 inches.
How do I estimate inches to centimeters in my head?
Multiply by 2.5. For 10 inches that gives 25 cm, close to the exact 25.4 cm, and the shortcut runs only about 1.6 percent low.