How to Convert Inches to Centimetres (in to cm)
Length conversions come up when reading overseas furniture specs, cycling the Round Island Route in kilometres while a foreign app shows miles, or checking marine distances in the Singapore Strait in nautical miles. This guide shows how to convert inches into centimetres by hand, with examples and a quick-reference table.
The conversion
To convert inches to centimetres, multiply the value by 2.54. To go the other way, divide by the same number (or multiply by 0.3937007874). For a quick estimate, multiply by about 2.5.
Centimetres = inches × 2.54
Worked examples
- 3 in = 7.62 cm
- 12.5 in = 31.75 cm
- 75 in = 190.5 cm
Inches to Centimetres table
| Inches | Centimetres |
|---|---|
| 1 in | 2.54 cm |
| 2 in | 5.08 cm |
| 5 in | 12.7 cm |
| 10 in | 25.4 cm |
| 20 in | 50.8 cm |
| 25 in | 63.5 cm |
| 50 in | 127 cm |
| 100 in | 254 cm |
| 250 in | 635 cm |
| 500 in | 1,270 cm |
| 1,000 in | 2,540 cm |
Common questions
Is in to cm exact?
The factors used here are the internationally defined values where they exist; results are rounded for display only.
How do I convert back?
Use the Centimetres to Inches converter.
Mistakes to avoid
Forgetting squared and cubed units
Area and volume factors are the length factor squared or cubed, so 1 m² is about 10.76 sq ft, not 3.28.
Multiplying when you should divide
Converting to a smaller unit gives a bigger number, and converting to a larger unit gives a smaller one. If your answer moves the wrong way, you have inverted the factor.
Mixing similar-sounding units
US and imperial gallons, pints and tons are different sizes, and decimal kilobytes differ from binary kibibytes.
Background
A conversion table is handy for common values, but a calculator is faster and avoids interpolation errors for anything in between.
Unit conversion is simply multiplication by a fixed ratio. The ratio between two units of the same quantity never changes, so once you know it you can convert any value in either direction.
Singapore adopted the metric system in the 1970s, replacing imperial units and traditional Chinese measures in most official uses. Metric units are now standard in schools, trade and government, but older units survive in property, markets and imported goods.
For any value, use the Inches to Centimetres Converter or browse all length converters.
Run your own numbers: Inches to Centimetres Converter