Convert inches to centimeters instantly. Enter any inch value and get the exact centimeter equivalent, plus the formula and a full reference table.
The conversion factor is derived from SI base values:
The inch-to-centimeter ratio of exactly 2.54 was adopted internationally in 1959.
| Inches (in) | Centimeters (cm) |
|---|---|
| 1 in | 2.54 cm |
| 2 in | 5.08 cm |
| 3 in | 7.62 cm |
| 6 in | 15.24 cm |
| 12 in | 30.48 cm |
| 24 in | 60.96 cm |
| 36 in | 91.44 cm |
| 48 in | 121.92 cm |
| 60 in | 152.4 cm |
| 72 in | 182.88 cm |
1 inch equals exactly 2.54 centimeters. This is an exact definition adopted by the US, UK, and Commonwealth countries in 1959 as part of the International Yard and Pound Agreement.
For a quick mental estimate, multiply inches by 2.5. For example, 10 in ≈ 25 cm (exact: 25.4 cm). The error is under 2%, which is fine for rough comparisons.
Convert feet to inches first (1 ft = 12 in), add the remaining inches, then multiply the total by 2.54. Example: 5 ft 8 in = (5 × 12) + 8 = 68 in × 2.54 = 172.72 cm.
Yes. The international inch is exactly 25.4 mm (2.54 cm) in all countries that use it. Before 1959, the US and UK used slightly different inch lengths - the difference was less than 2 parts per million.
The word "inch" comes from the Latin uncia, meaning one-twelfth - originally one-twelfth of a Roman foot. The exact 2.54 cm definition was set in 1959 to harmonize US and UK measurements.