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Convert cm to inches
Convert centimeter (cm) to inch (in) instantly. Free, no signup, nothing is uploaded — everything runs in your browser.
Centimeter to Inch conversion table
| Centimeter [cm] | Inch [in] |
|---|---|
| 0.01 | 0.00393701 |
| 0.1 | 0.03937008 |
| 1 | 0.39370079 |
| 2 | 0.78740157 |
| 3 | 1.18110236 |
| 5 | 1.96850394 |
| 10 | 3.93700787 |
| 20 | 7.87401575 |
| 50 | 19.68503937 |
| 100 | 39.37007874 |
| 1,000 | 393.7007874 |
How to convert centimeter to inch
inches = cm ÷ 2.54
Example: 15 cm = 15 ÷ 2.54 = 5.9055 in
To convert back (inch to centimeter): cm = inches × 2.54
What is a centimeter?
A centimeter (cm) is a unit of length in the metric system, equal to one hundredth of a meter. It is the everyday unit for body measurements, paper sizes, and small object dimensions in most of the world.
What is a inch?
An inch (in) is a unit of length in the US customary and imperial systems, defined as exactly 25.4 millimeters since the 1959 international yard agreement. It is the standard unit for screen sizes, paper, and small mechanical parts in the United States.
When do you need to convert centimeter to inch?
Converting centimeter measurements to inches is most common when buying or building for a US audience: TV and monitor screen sizes (a 55" TV is about 140 cm diagonal), phone displays, laptop screens, and tablet dimensions are all quoted in inches. If a manufacturer lists a screen as 32 cm tall, you divide by 2.54 to get the 12.6-inch spec sheet equivalent.
Clothing, tailoring, and sewing is the other large use case. European and Asian clothing sizes are typically in centimeters (chest 96 cm, waist 80 cm, inseam 81 cm), while North American patterns are in inches. A pattern that says "cut a 60 cm strip" needs the inch equivalent for US-made patterns, which is 23.6 in. Off by even 1 cm here and the garment does not fit.
Woodworking, 3D printing, and machining all need cm ↔ in conversion. CNC g-code, Fusion 360 designs, and printer firmware frequently mix the two systems depending on the design origin. A print bed advertised as 220 × 220 mm is 8.66 × 8.66 inches; a board foot calculation requires inches but the lumber may be measured in centimeters at the lumberyard.
Frequently asked questions
What is 1 cm in inches?
1 cm = 0.3937 inches, exactly. The conversion is exact by international definition (1 inch = 2.54 cm, agreed in 1959), so there is no rounding error in the formula — only in how many decimal places you keep.
How do I convert cm to inches without a calculator?
Divide by 2.54. For a rough mental estimate, divide by 2.5 (slightly off but within 1.6%). So 50 cm is "about 20 inches" (actual: 19.69 in) and 100 cm is "about 40 inches" (actual: 39.37 in). For 30 cm, the actual is 11.81 in, which rounds to 12 in for most purposes.
Is a centimeter the same as an inch on a ruler?
No. A centimeter is shorter. 1 inch = 2.54 cm, so a centimeter is just under 0.4 of an inch. On a typical dual-scale ruler, the cm marks are closer together than the inch marks. The half-inch mark sits at 1.27 cm, the quarter-inch at 0.635 cm.
Why is the answer 0.3937 and not exactly 0.4?
Because 2.54 is the exact international definition of an inch in centimeters. 1 ÷ 2.54 = 0.39370078740157... repeating. Rounded to 4 decimal places it is 0.3937. Any value that claims 1 cm = 0.4 in exactly is wrong by 1.6%. For engineering work, use the full 0.3937007... value; for everyday conversions, 0.3937 is more than enough precision.