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cm to inches
Convert centimeters to inches instantly with an exact factor based on 1 inch = 2.54 cm.
1 centimeter equals 0.3937 inches. Use this free cm to inches converter when a metric measurement needs an imperial answer for the US. The relationship is exact because one inch is defined as 2.54 centimeters. Enter a value above, read the inches result, and use the chart below for common lengths without doing the math by hand. The same factor powers every row in the table, so tool and chart stay aligned.
How to convert cm to inches
Divide centimeters by 2.54. In short: inches = cm ÷ 2.54.
Example: 10 cm ÷ 2.54 = 3.94 inches. So 10 centimeters is 3.94 inches.
Do not replace 2.54 with 2.5 unless you only need a rough field estimate. Two decimal places are enough for most shopping and school answers.
cm to inches conversion chart
Common centimeter values converted to inches, rounded to two decimal places.
| Centimeters (cm) | Inches (in) |
|---|---|
| 1 cm | 0.39 in |
| 2 cm | 0.79 in |
| 3 cm | 1.18 in |
| 4 cm | 1.57 in |
| 5 cm | 1.97 in |
| 10 cm | 3.94 in |
| 15 cm | 5.91 in |
| 20 cm | 7.87 in |
| 25 cm | 9.84 in |
| 30 cm | 11.81 in |
| 40 cm | 15.75 in |
| 50 cm | 19.69 in |
| 75 cm | 29.53 in |
| 100 cm | 39.37 in |
Scan the chart for quick checks. Use the converter above when your number is not listed.
Common cm to inches conversions
5 cm is 1.97 inches. That is a common small object size in product specs.
30 cm is 11.81 inches, just under one foot. 100 cm is 39.37 inches, a little more than a yardstick.
For height context, 180 cm is about 70.87 inches, or roughly 5 feet 11 inches.
When a height is only in centimeters, convert to total inches first. Then split into feet and leftover inches if a US form asks for both.
For packaging, convert the metric side first. Then compare with US size charts side by side.
Why the US uses inches while many countries use centimeters
The United States still relies on inches, feet, and yards for everyday length. Most of the world measures the same lengths in millimeters, centimeters, and meters.
That split shows up in clothing, screens, DIY, and travel. A cm to inches step helps you compare product sizes written in metric with US packaging and store rules. Clear unit labels on notes prevent mix-ups later.
Students also use cm to inches when a worksheet switches unit systems mid problem. Showing the factor keeps the work checkable.
Frequently asked questions
How many inches is 5 cm?
5 cm equals 1.97 inches (5 ÷ 2.54).
How many inches is 10 cm?
10 cm equals 3.94 inches.
How many inches is 30 cm?
30 cm equals 11.81 inches, just under 12 inches (one foot).
Is 1 cm exactly 0.4 inches?
No. 1 cm is exactly 1 ÷ 2.54 inches, which is about 0.3937 inches.
How do I convert cm to feet and inches?
Convert cm to total inches first, then divide by 12 for feet and keep the remainder as inches.
More free converters
Need the reverse tool? Open inches to cm. For all length units, visit the length converter hub. Related: mm to inches and feet to meters.
Length definitions follow international agreements. See NIST - SI units for length for official SI length context.