Inches to CM
Convert inches to centimetres instantly — 1 inch is exactly 2.54 cm. Includes a 1–12 inch table for quick lookups.
Fast, easy and free — your answer appears as you type, and whatever you enter stays on your device.
One inch is exactly 2.54 centimetres, so converting inches to centimetres is a single multiplication. Type a value below for the precise answer, or use the table for the first twelve inches.
How to use it
- Type the inch valueThe centimetre answer appears as you type — no button to press.
- Or go the other waySwap flips the direction to centimetre → inch in one tap.
- Check the workingThe exact factor or formula used is shown beneath the answer, so the result is checkable, not just asserted.
Inches 1–12 in centimetres
| in | cm |
|---|---|
| 1 in | 2.54 cm |
| 2 in | 5.08 cm |
| 3 in | 7.62 cm |
| 4 in | 10.16 cm |
| 5 in | 12.7 cm |
| 6 in | 15.24 cm |
| 7 in | 17.78 cm |
| 8 in | 20.32 cm |
| 9 in | 22.86 cm |
| 10 in | 25.4 cm |
| 11 in | 27.94 cm |
| 12 in | 30.48 cm |
The quick rule for your head
Multiply by 2.5 and add a little: 8 inches × 2.5 = 20, plus a touch ≈ 20.3 cm (exact: 20.32). For screen sizes, doubling and adding half again gets you close instantly — a 24-inch monitor is about 61 cm across the diagonal. Since 2.54 is exact, the tool's answer never carries rounding error; only your shortcut does.
Where this conversion shows up
Inches arrive from American product listings — screens, wheels, pipes, picture frames — and need to become centimetres before you can check them against a European tape measure. Woodworkers meet it constantly, since US plans dimension in inches while European timber is sold in millimetres and centimetres.
Need other units too? The fulllength converter handles every pair and shows the exact factor behind each answer. For the opposite direction, use CM to Inches.
Questions people ask
How many cm is 1 inch?
Exactly 2.54 cm. This has been the definition of the inch since 1959, so it is one of the few conversions with literally zero rounding.
What is 5 feet 10 inches in cm?
70 inches total, which is 177.8 cm. For any feet-and-inches height, multiply the feet by 12, add the inches, then multiply by 2.54 — or use our cm-to-feet page in reverse.
Are screen inches the same inches?
Yes — a 55-inch TV is 55 × 2.54 = 139.7 cm, measured diagonally. The diagonal is the catch: a 55-inch TV is only about 122 cm wide.
How accurate is rounding to 2.5?
About 1.6% low — fine for furniture, risky for joinery. Anything that must actually fit deserves the exact 2.54.