Inches to Centimeters Converter
Convert inches to centimeters by multiplying by exactly 2.54. Includes a conversion table, common screen and paper sizes, and how to convert feet and inches to centimeters.
Inches to centimeters
Formula
Multiply by exactly 2.54.
This is one of the rare conversions where the factor is exact rather than rounded. The 1959 international yard and pound agreement defined the inch as exactly 25.4 millimetres, so no precision is lost in either direction.
Worked example
Convert a 32 in waist:
And a 15.6 in laptop screen, measured diagonally:
Conversion table
| Inches (in) | Centimeters (cm) |
|---|---|
| 0.5 | 1.27 |
| 1 | 2.54 |
| 2 | 5.08 |
| 3 | 7.62 |
| 6 | 15.24 |
| 10 | 25.4 |
| 12 | 30.48 |
| 15.6 | 39.624 |
| 24 | 60.96 |
| 32 | 81.28 |
| 36 | 91.44 |
| 48 | 121.92 |
| 72 | 182.88 |
Converting feet and inches
Mixed imperial heights need the feet folded in first. Multiply the feet by 12, add the inches, then multiply the whole thing by 2.54.
For 5 ft 9 in:
Common heights:
- 5 ft 0 in = 152.4 cm
- 5 ft 4 in = 162.6 cm
- 5 ft 6 in = 167.6 cm
- 5 ft 9 in = 175.3 cm
- 6 ft 0 in = 182.9 cm
- 6 ft 3 in = 190.5 cm
Screen and paper sizes
Screens are sold by diagonal inches, which is why the centimetre equivalents look odd:
- 13.3 in laptop = 33.78 cm
- 15.6 in laptop = 39.62 cm
- 24 in monitor = 60.96 cm
- 27 in monitor = 68.58 cm
- 55 in television = 139.7 cm
- 65 in television = 165.1 cm
Paper runs the other way. A4 is metric at 21.0 × 29.7 cm, which is 8.27 × 11.69 in — close to US Letter at 8.5 × 11 in (21.59 × 27.94 cm) but not interchangeable, as anyone who has printed across the Atlantic knows.
FAQ
How many cm is 1 inch? Exactly 2.54 cm.
How many inches is 1 cm? 0.3937008 in, slightly under four tenths of an inch.
How do I convert inches to millimetres? Multiply by 25.4 instead — one inch is exactly 25.4 mm.
Is 2.54 an approximation? No. It is the definition of the inch, agreed internationally in 1959 and used ever since.
Why do rulers show both? Because a ruler marked in both units needs no conversion at all for rough work — and the exact 2.54 ratio means the 2.54 cm mark lands precisely on the 1 in mark.