Convert centimeters to inches
1 cm = 0.393700787 in · Formula and table below. Converting the other way? Inches to Centimeters →
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Other units
- Meter (m) 0.01
- Kilometer (km) 0.00001
- Decimeter (dm) 0.1
- Centimeter (cm) 1
- Millimeter (mm) 10
- Micrometer (µm) 10,000
- Nanometer (nm) 10,000,000
- Mile (mi) 0.000006214
- Yard (yd) 0.010936133
- Foot (ft) 0.032808399
- Inch (in) 0.393700787
- Nautical mile (nmi) 0.0000054
- Light year (ly) 1.057001×10⁻¹⁸
Reviewed on by the Skala Convert team
Divide centimetres by 2.54. Thirty centimetres is 11.81 inches.
How many inches is a centimeter?
in = cm ÷ 2.54, or 0.3937 inches per centimetre.
The 2.54 is exact. It was fixed in 1959, when the United States, the United Kingdom and four other countries agreed on a common inch; before that the American and British inches differed by about two parts per million.
What are carry-on size limits in inches?
Airlines outside North America set cabin bag limits in centimetres — commonly 55 × 40 × 20 cm. That is 21.65 × 15.75 × 7.87 inches. A bag sold in the US as "22 inch carry-on" is 55.9 cm tall before counting wheels and handles, which is why it can be rejected at a European gate. Measure the whole bag in centimetres, wheels included.
How do you read inches as fractions?
A ruler marked in inches is divided into halves, quarters, eighths and sixteenths, not tenths. To use a result like 11.81 in on a tape measure, take the decimal part and multiply by 16: 0.81 × 16 = 13, so the mark is 11 13/16 inches.
What sizes are usually given in inches?
- Jeans — a 32 inch waist is 81 cm
- Bike frames — mountain bikes often list 17 or 19 inch frames (43 and 48 cm)
- Wheels — a 29 inch mountain bike wheel is a nominal size, not a measured one
For heights, where the answer should be feet and inches, use cm to feet.
Where does the 2.54 divisor come from?
From the international inch. NIST Special Publication 811, the US guide to the SI gives the inch as exactly 0.0254 m, the value set in 1959 when the national laboratories of the US, the UK, Canada, Australia, New Zealand and South Africa agreed on a common yard of 0.9144 m, announced in the US by the National Bureau of Standards. The United Kingdom adopted the same yard in its Weights and Measures Act 1963. Dividing by 2.54 is therefore exact; only the displayed result is rounded.
Formula
Inches = Centimeters × 0.393700787
10 cm = 3.937008 in
Conversion table
| cm | in |
|---|---|
| 1 | 0.393700787 |
| 2 | 0.787401575 |
| 5 | 1.968504 |
| 10 | 3.937008 |
| 20 | 7.874016 |
| 25 | 9.84252 |
| 50 | 19.685039 |
| 100 | 39.370079 |
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Frequently asked questions
How many inches is 30 cm?
11.81 inches.
Is 55 cm a 22 inch bag?
No. 55 cm is 21.65 inches; a 22 inch bag is 55.9 cm.
How do I turn decimal inches into a fraction?
Multiply the decimal part by 16 and round to get sixteenths of an inch.