Inches to cm converter
Type any inch value and get centimeters instantly - 1 inch = 2.54 cm, exactly
12 inches =30.48 centimeters
12 in × 2.54 = 30.48 cm
Common inches to cm conversions
| Inches | cm | Inches | cm |
|---|---|---|---|
| 1 in | 2.54 cm | 12 in | 30.48 cm |
| 2 in | 5.08 cm | 16 in | 40.64 cm |
| 3 in | 7.62 cm | 20 in | 50.80 cm |
| 4 in | 10.16 cm | 24 in | 60.96 cm |
| 6 in | 15.24 cm | 30 in | 76.20 cm |
| 8 in | 20.32 cm | 36 in | 91.44 cm |
| 10 in | 25.40 cm | 48 in | 121.92 cm |
Looking for the reverse? Use the cm to inches converter, or see the full1-100 cm conversion table.
The formula
centimeters = inches × 2.54. The inch is defined by international agreement as exactly 2.54 centimeters, so every conversion between the two is exact. To go the other way, divide by 2.54: 30 cm ÷ 2.54 = 11.81 in.
Quick mental estimate: multiply by 2.5 and add 1% - 12 × 2.5 = 30, plus 0.3% gives about 30.5 cm. Accurate enough to check a printout at a glance.
FAQ
How do I convert inches to cm?
Multiply the inch value by 2.54. One inch is defined as exactly 2.54 centimeters, so 12 in x 2.54 = 30.48 cm and 6 in x 2.54 = 15.24 cm. The conversion is exact - nothing is rounded until you choose a precision.
What is 12 inches in cm?
12 inches is exactly 30.48 cm. This is the length of a standard 1-foot ruler, which is why 30 cm rulers and 12 inch rulers are almost, but not quite, the same length.
What is 6 inches in cm?
6 inches is exactly 15.24 cm (6 x 2.54). That is the length of a half-size ruler and roughly the diagonal of a large phone screen.
Is a 12 inch ruler the same as a 30 cm ruler?
No - a 12 inch ruler is 30.48 cm, so it is 0.48 cm longer than a 30 cm ruler. On printed layouts and screen captures that half-millimeter difference is enough to throw off alignment.
Convert while you measure
If you are measuring something on screen, you do not need to convert at all: theonline ruler draws centimeter, millimeter, and inch scales on the same edge, calibrated to your display, so both numbers are always on the object you are measuring. For paper, see the printable 12-inch and 30-cm rulers.