Convert inches to centimetres in one step. Type a value, change the units if you need a different pair, and the answer updates as you type, with the reverse rate and a quick reference list.
Results are estimates for planning. Check the figures before you make a financial or health decision.
How to convert inches to centimetres
Multiply the number of in by 2.54 to get cm:
cm = in × 2.54
To go the other way, divide by 2.54 (or multiply by 0.393701). The converter stores each unit as a multiple of a base unit, so you can also pick any other pair of units from the same group.
Worked example
Using the default values in the converter above:
| Input | Value |
|---|---|
| Value | 12 |
| From | Inches |
| To | Centimetres |
12 inches equals 30.48 centimetres
Inches to CM reference table
| Inches | Centimetres |
|---|---|
| 1 in | 2.54 cm |
| 2 in | 5.08 cm |
| 5 in | 12.7 cm |
| 10 in | 25.4 cm |
| 20 in | 50.8 cm |
| 50 in | 127 cm |
| 100 in | 254 cm |
| 500 in | 1,270 cm |
| 1,000 in | 2,540 cm |
Tips and common mistakes
The inch, foot, yard and mile are defined exactly in metric terms: 1 inch is 25.4 mm, 1 foot is 0.3048 m and 1 mile is 1.609344 km. The factors used here are therefore exact, and any rounding comes only from the number of digits shown.
The most common mistake is treating the part after the decimal point of a foot as inches. 5.5 ft means five and a half feet, which is 5 ft 6 in, not 5 ft 5 in. Check that you are reading a decimal and not a feet-and-inches pair.
For quick mental maths, remember that an inch is about 2.5 cm, a foot is about 30 cm, a metre is a little over 3 ft 3 in, and a mile is about 1.6 km.
Frequently asked questions
How many centimetres are in 1 in?
1 in equals 2.54 centimetres.
How do I convert in to cm by hand?
Multiply the in figure by 2.54. For example, 12 in × 2.54 = 30.48 cm.
How do I convert cm back to in?
Divide the cm figure by 2.54, or multiply it by 0.393701. For example, 30.48 cm is 12 in.
Is this conversion exact?
The inch, foot, yard and mile are defined exactly in metric terms, so the factor is exact. Any difference comes only from rounding.