Centimeters to Inches Converter
1 centimeter (cm) equals 0.393700787402 inches (in).
Quick answer
To convert centimeters to inches, divide by 2.54. One centimeter is about 0.3937 inches, and 10 cm is just under 4 inches (3.937 in).
- 1 centimeter = 0.3937007874 inches
- 1 inch = 2.54 centimeters
- Formula: in = cm ÷ 2.54
- Quick estimate: divide by 2.5 and take off a little: 30 cm ÷ 2.5 = 12, real answer 11.8 in.
1 centimeter = 0.3937007874 inches
How to convert centimeters to inches
in = cm ÷ 2.54
To convert centimeters to inches, divide the number of centimeters by 2.54.
Example: 42 cm to in
- Start with the value in centimeters: 42 cm.
- Divide by 2.54: 42 ÷ 2.54 = 16.53543307.
- Result: 42 centimeters = 16.53543307 inches.
Going the other way, 1 inch = 2.54 centimeters, so to convert inches back to centimeters you multiply by the same number. See inches to centimeters.
Where the conversion factor comes from
Since the international yard and pound agreement of 1959, the inch has been defined as exactly 2.54 centimeters. Before that, the US and the UK used slightly different inches (the US inch was 2.540005 cm). The 1959 definition made the conversion exact, so 2.54 is not a rounded number: every inch-to-centimeter conversion is a multiplication by exactly 2.54.
So converting centimeters to inches is a division by 2.54, or equivalently a multiplication by 0.393700787…, which is 1/2.54 rounded.
Mental math: cm to in in your head
Dividing by 2.54 in your head is awkward, so divide by 2.5 instead (double the number, then divide by 5) and knock off about 1.6%. For example, 40 cm: 40 × 2 = 80, ÷ 5 = 16, minus a little = 15.7 inches (exact: 15.748).
Another handy anchor: 10 cm ≈ 4 inches and 30 cm ≈ 1 foot (11.8 in). For body measurements and furniture, those two are usually close enough.
When you need to convert centimeters to inches
- Buying clothes from US or UK sites when you know your size in centimeters (waist, inseam, chest).
- Comparing screen, TV and luggage sizes, which are often given in inches.
- Following US sewing, woodworking or crafting patterns with a metric tape measure.
- Converting your height from cm to feet and inches for forms and dating apps.
Common mistakes
- Multiplying by 2.54 instead of dividing: centimeters are smaller than inches, so the number of inches must be smaller.
- Using 2.5 as if it were exact: over a meter the error is almost 2 cm.
- Treating 5.7 feet as 5 feet 7 inches: 170 cm is 5.58 ft, which is 5 ft 7 in, not 5 ft 5.8 in.
Everyday centimeters in inches
| Example | Centimeters | Inches |
|---|---|---|
| Credit card width | 8.56 cm | 3.3701 in |
| Letter-size envelope width | 11.4 cm | 4.4882 in |
| A4 paper width | 21 cm | 8.2677 in |
| School ruler | 30 cm | 11.811 in |
| Newborn baby length (average) | 50 cm | 19.685 in |
| Carry-on suitcase height limit (many airlines) | 55 cm | 21.654 in |
| Average US man's height | 175.4 cm | 69.055 in |
Converting a height? The height converter works in feet and inches directly, for example 5′7″ in cm or 170 cm in feet.
Centimeters to inches conversion table
| Centimeters (cm) | Inches (in) |
|---|---|
| 0.1 cm | 0.03937007874 in |
| 0.2 cm | 0.07874015748 in |
| 0.3 cm | 0.1181102362 in |
| 0.4 cm | 0.157480315 in |
| 0.5 cm | 0.1968503937 in |
| 0.6 cm | 0.2362204724 in |
| 0.7 cm | 0.2755905512 in |
| 0.8 cm | 0.3149606299 in |
| 0.9 cm | 0.3543307087 in |
| 1 cm | 0.3937007874 in |
| 1.5 cm | 0.5905511811 in |
| 2 cm | 0.7874015748 in |
| 2.5 cm | 0.9842519685 in |
| 3 cm | 1.181102362 in |
| 3.5 cm | 1.377952756 in |
| 4 cm | 1.57480315 in |
| 4.5 cm | 1.771653543 in |
| 5 cm | 1.968503937 in |
| 6 cm | 2.362204724 in |
| 7 cm | 2.755905512 in |
| 7.5 cm | 2.952755906 in |
| 8 cm | 3.149606299 in |
| 9 cm | 3.543307087 in |
| 10 cm | 3.937007874 in |
| 11 cm | 4.330708661 in |
| 12 cm | 4.724409449 in |
| 13 cm | 5.118110236 in |
| 14 cm | 5.511811024 in |
| 15 cm | 5.905511811 in |
| 16 cm | 6.299212598 in |
| 17 cm | 6.692913386 in |
| 18 cm | 7.086614173 in |
| 19 cm | 7.480314961 in |
| 20 cm | 7.874015748 in |
| 21 cm | 8.267716535 in |
| 22 cm | 8.661417323 in |
| 23 cm | 9.05511811 in |
| 24 cm | 9.448818898 in |
| 25 cm | 9.842519685 in |
| 26 cm | 10.23622047 in |
More cm to in values
- 27 cm
- 28 cm
- 29 cm
- 30 cm
- 31 cm
- 32 cm
- 33 cm
- 34 cm
- 35 cm
- 36 cm
- 37 cm
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- 600 cm
- 700 cm
- 800 cm
- 900 cm
- 1,000 cm
- 1,200 cm
- 1,500 cm
- 2,000 cm
- 2,500 cm
- 3,000 cm
- 4,000 cm
- 5,000 cm
- 10,000 cm
What is a centimeter?
The centimeter (also spelled centimetre) is a metric unit of length equal to one hundredth of a meter.
What is an inch?
The inch is a unit of length in the imperial and US customary systems equal to exactly 2.54 centimeters.
Convert centimeters to other units
Convert other units to inches
Frequently asked questions
How many inches are in a centimeter?
One centimeter is 0.3937007874 inches.
How many centimeters are in an inch?
One inch is 2.54 centimeters.
What is the formula to convert centimeters to inches?
in = cm ÷ 2.54.
Is 1 inch exactly 2.54 cm?
Yes. Since 1959 the inch has been defined as exactly 2.54 centimeters, so conversions between inches and centimeters are exact.
How many inches is 100 cm?
100 cm is 39.37 inches, or 3 feet 3.37 inches.