Multiply inches by 2.54 to get centimetres. Screen diagonals, wheel sizes and picture frames are often given in inches, while metric countries quote centimetres or millimetres.
How to use the Inches to cm Converter
- Type the number of inches into the Inches field. Decimals such as 6 are fine.
- Read the answer in Centimetres – it updates as you type, with no button to press.
- To convert the other way, type into Centimetres and the inches are recalculated.
- Press Copy results to copy both values with the page title, or Copy link to share this exact conversion.
This page converts only in ⇄ cm. Need a different unit? Use the general length converter, where you can choose any “from” and “to” unit.
How it works
Both units measure length, so they are always in the same ratio: one inch equals 2.54 centimetres. The calculator multiplies the number of inches you type by 2.54 to give centimetres, and when you type into the centimetres field it divides by the same factor to give inches. Because the ratio never changes, doubling the inches always doubles the centimetres. Results are calculated at full precision and rounded only for display (up to eight decimal places, with very large or small values shown in scientific notation).
How to convert inches to centimetres
- Write down the value in inches, for example 12 in.
- Multiply by the conversion factor 2.54 (because 1 inch = 2.54 cm).
- 12 × 2.54 = 30.48 cm.
- To go back from centimetres to inches, divide by 2.54 – or multiply by 0.39370079.
in to cm conversion table
| Inches | Centimetres | Centimetres | Inches |
|---|---|---|---|
| 0.25 in | 0.635 cm | 1 cm | 0.39370079 in |
| 1 in | 2.54 cm | 2 cm | 0.78740157 in |
| 2 in | 5.08 cm | 5 cm | 1.9685039 in |
| 4 in | 10.16 cm | 10 cm | 3.9370079 in |
| 6 in | 15.24 cm | 20 cm | 7.8740157 in |
| 8 in | 20.32 cm | 50 cm | 19.685039 in |
| 12 in | 30.48 cm | 100 cm | 39.370079 in |
| 18 in | 45.72 cm | 1,000 cm | 393.70079 in |
| 32 in | 81.28 cm | ||
| 43 in | 109.22 cm | ||
| 55 in | 139.7 cm | ||
| 75 in | 190.5 cm |
What is an inch?
The inch has been defined as exactly 25.4 mm since 1959. It is used in the U.S. for almost everything and worldwide for screen sizes, wheel and tyre sizes, pipe threads and many tools.
What is a centimetre?
A centimetre is one hundredth of a metre (10 mm). It is the everyday metric unit for body height, clothing, furniture and school rulers.
Quick mental conversion
For a fast estimate, multiply inches by about 2.5 to get centimetres; the error is about 1.6%. Use the calculator above when you need the exact figure.
Common mistakes to avoid
Mixing the international foot (0.3048 m) with the old u.s. survey foot, confusing nautical and statute miles, and writing decimal feet such as 5.5 ft as “5 ft 5 in” (it is 5 ft 6 in).
Formula
1 in = 2.54 cm1 cm = 0.39370079 incm = in × 2.54Worked example
Inputs — Inches: 12 in.
Results — Centimetres = 30.48 cm.
Frequently asked questions
How many cm is 12 inches?
30.48 cm, one foot.
How big is a 55-inch TV in cm?
139.7 cm diagonally.
How do I convert inches to centimetres?
Multiply the number of inches by 2.54. For example, 12 in × 2.54 = 30.48 cm.
How do I convert centimetres back to inches?
Divide by 2.54 (or multiply by 0.39370079), or simply type the value into the centimetres field above.
What is 10 in in centimetres?
10 in = 25.4 cm.
What is 5 in in centimetres?
5 in = 12.7 cm.
Is this conversion exact?
Yes. The factor comes from the official definitions of both units (NIST and the SI), so the only difference you may see is rounding in the last displayed digit.
Can I convert to other units on this page?
This page converts only between inches and centimetres. To pick any length unit, use the general length converter linked under Related calculators.
What formula does the Inches to cm Converter use?
1 in = 2.54 cm.