Centimetres to Inches Converter (cm to in)
Convert centimetres to inches instantly. 1 cm = 0.3937 in. Includes the formula, a full conversion table and a calculator that works offline.
The formula
To convert centimetres to inches, multiply by 0.3937:
in = cm × 0.3937Going the other way, divide instead — or multiply by 2.54, which is the same thing:
cm = in × 2.54Centimetres to Inches conversion table
| Centimetres | Inches |
|---|---|
| 1 cm | 0.3937 in |
| 2 cm | 0.7874 in |
| 3 cm | 1.181 in |
| 4 cm | 1.575 in |
| 5 cm | 1.969 in |
| 6 cm | 2.362 in |
| 7 cm | 2.756 in |
| 8 cm | 3.15 in |
| 9 cm | 3.543 in |
| 10 cm | 3.937 in |
| 15 cm | 5.906 in |
| 20 cm | 7.874 in |
| 25 cm | 9.843 in |
| 30 cm | 11.811 in |
| 40 cm | 15.748 in |
| 50 cm | 19.685 in |
| 75 cm | 29.528 in |
| 100 cm | 39.37 in |
| 250 cm | 98.425 in |
| 500 cm | 196.85 in |
| 1000 cm | 393.7 in |
Inches to Centimetres
| Inches | Centimetres |
|---|---|
| 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 |
What that actually looks like
A conversion factor is hard to judge on its own. These are quantities most people already have a feel for, converted for you:
- An A4 sheet is 21 cm wide — 8.268 in
- A credit card is 8.56 cm long — 3.37 in
- An average adult hand span is about 20 cm — 7.874 in
- A standard ruler is 30 cm — 11.811 in
Why both units are still in use
Almost every country measures length in metres and centimetres. The United States is the significant exception, and the United Kingdom is genuinely split: road signs are in miles, a person's height is in feet and inches, but a bottle of water is in millilitres and a running race is in kilometres. That is why this conversion comes up so often — not because one system is replacing the other, but because both are in daily use side by side.
Mistakes worth avoiding
The most common mistake is mixing feet and inches in one number. Five foot ten is 5.833 feet, not 5.10 — the inches are twelfths, not hundredths. Convert the inches separately, or work in inches throughout and divide at the end.
The other habit worth breaking is rounding too early. Convert first, round once at the end, and you avoid the drift that turns a small approximation into a visible error by the third calculation.
Doing it in your head
When you only need a rough answer, divide by 2.5 — which lands within 1.6 percent of the true value. Ten centimetres works out at roughly 4 inches that way, against 3.937 exactly. An estimate is enough for deciding whether something will fit or whether a figure sounds plausible. When the number has to be right — because you are buying, cooking or building to it — use the calculator and let it carry the decimals.
Common questions
How many inches are in one centimetre?
One centimetre equals 0.3937 inches. The calculator above handles any value, including decimals and very large numbers, and updates as you type.
Is this an exact conversion?
The factor is accurate to the precision shown, which is far beyond what any practical measurement requires. The table rounds for readability; the calculator does not.
Does this work offline?
Yes. The conversion runs in your browser with no network request, so it works on a plane, in a basement, or on a phone with no signal once the page has loaded.