Do not divide by 2.5 for an exact result
The exact relationship is one inch equals 2.54 centimetres; 2.5 is only a rough mental estimate.
Unit converter
CM to Inches Converter
Convert centimetres to inches instantly. Centimetres and product sizing. See the formula, worked examples and practical reference values.
How to convert cm to in
Centimetres to inches is frequently needed for screens, clothing, crafts and product dimensions published in different measurement systems.
Formula: in = cm × 0.393701
Reverse formula: cm = in × 2.54
Worked example
180 cm = 70.866142 in
- = 1.8 m
- = 5.905512 ft
- = 1.968504 yd
Avoid these errors
Common mistakes
Screen size is measured diagonally
Converting a screen diagonal does not reveal its width or height without the aspect ratio.
Useful for: Small metric measurements converted to inches.
Common cm to in conversions
| centimetres | inches |
|---|---|
| 1 cm | 0.393701 in |
| 2.54 cm | 1 in |
| 5 cm | 1.968504 in |
| 10 cm | 3.937008 in |
| 25 cm | 9.84252 in |
| 50 cm | 19.685039 in |
| 100 cm | 39.370079 in |
| 180 cm | 70.866142 in |
About the units
A centimetre is a metric unit represented by cm. A inch is an imperial unit represented by in. Calculations use the same authoritative registry as the full length converter, retaining full precision until display.
Sources and definitions
NIST — SI units and conversion guidance
Conversion constants come from the shared EzyCalculator unit registry. See how calculations are reviewed and tested.