Centimetres to Inches Converter
Convert centimetres to inches in one step. Type a length in cm and get inches to eight significant digits, along with millimetres, feet and metres. Swap the units to go from inches back to centimetres.
Centimetres to inches converter
How to use the centimetres to inches converter
- Enter the centimetres. Type the number of centimetres you want to convert. Decimals work, and so do fractions entered as decimals.
- Check the units. The converter starts as centimetres to inches. Use the From and To menus to change either unit, or press Swap to reverse them.
- Read the result. The answer appears at the top, with the conversion factor and the same value in other common units underneath.
- Copy or print. Copy the result to paste into a message, or print a clean summary to keep with your plans.
How to convert centimetres to inches
inches = centimetres ÷ 2.54
centimetres = inches × 2.54
Since 1959 the international inch has been exactly 2.54 centimetres, so this conversion is exact rather than approximate. Dividing by 2.54 is the same as multiplying by 0.393700787. For a quick mental estimate, multiply by 0.4 and take off a little.
Worked examples
A screen size. TV sizes are diagonals, so a 55-inch TV measures 55 × 2.54 = 139.7 cm corner to corner.
A paper size. A4 paper is 21 × 29.7 cm, which is 8.268 × 11.69 inches.
A waist measurement. 80 cm is 31.496 inches, and 100 cm is 39.37 inches.
A small length. 2.5 cm is 0.98425 inches, just under 1 inch.
Centimetres to inches table
| cm | in |
|---|---|
| 1 cm | 0.3937 in |
| 2 cm | 0.7874 in |
| 5 cm | 1.969 in |
| 10 cm | 3.937 in |
| 15 cm | 5.906 in |
| 20 cm | 7.874 in |
| 25 cm | 9.843 in |
| 30 cm | 11.81 in |
| 50 cm | 19.69 in |
| 100 cm | 39.37 in |
| 150 cm | 59.06 in |
| 200 cm | 78.74 in |
Where this conversion comes up
Product sizes, tailoring, luggage, screens and furniture are often given in centimetres outside the US and in inches inside it. When you buy online from another country, convert the key dimensions before ordering. For feet and inches, use the cm to feet and inches converter, and for engineering parts the inches to mm converter is more precise.
Features
- Convert centimetres to inches and back, with a Swap button.
- Other common units shown at once, so you rarely need a second conversion.
- Exact definitions from NIST, with 8 significant digits.
- Copy result, reset and a printable report in five themes on A4 or Letter.
Related converters and calculators
Convert fractions with the inches to mm converter, express heights with the cm to feet and inches converter, or try the all-in-one unit converter. For building projects, the inches to decimal converter turns fractions into decimals.
Frequently asked questions
How many inches is 1 cm?
One centimetre is 0.3937 inches, found by dividing by 2.54. So 10 cm is 3.937 inches and 100 cm is 39.37 inches.
How do you convert cm to inches by hand?
Divide the centimetres by 2.54. For a rough answer, multiply by 0.4: 50 cm × 0.4 = 20 inches, against an exact 19.69 inches.
Is the 2.54 factor exact?
Yes. The US and other countries adopted the international yard and pound in 1959, which fixed the inch at exactly 25.4 millimetres, or 2.54 cm.
How many cm is an inch?
One inch is exactly 2.54 centimetres, or 25.4 millimetres. Multiply inches by 2.54 to get centimetres.
How do I convert cm to inches and feet?
Divide by 2.54 for inches, then divide by 12 for feet. For example 180 cm is 70.87 inches, or 5 feet 10.9 inches. The cm to feet and inches converter does this for you.
Why do some sizes round differently?
Shops often round to the nearest quarter or half inch. The calculator shows the exact value, so round it to match the precision you need.
How do I convert cm to mm?
Multiply by 10, because there are 10 millimetres in a centimetre. The calculator lists millimetres in the results so you can see both at once.
Related calculators
Inches to mm Converter
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CM to Feet and Inches Converter
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Feet to Inches Converter
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Unit Converter
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Sources and references
About this calculator
Written and maintained by Rashid Mehmood, founder of CalcTen. The formulas are unit-tested against hand-worked examples, and the content is reviewed whenever product sizes or guidance change. Last updated 14 November 2026. See our editorial policy.
Conversion factors come from NIST and other standards bodies, and results are rounded for display. For safety-critical work such as medicines, engineering or navigation, verify with an authoritative source. Read the disclaimer.