Centimeters to inches, both ways.

How do I convert cm to inches?

Divide the centimeter value by 2.54: inches = cm ÷ 2.54. 1 inch is defined as exactly 2.54 cm by international agreement, so this conversion is exact, not an approximation.

How do I convert inches to cm?

Multiply the inch value by 2.54: cm = inches × 2.54. For example, 10 inches × 2.54 = 25.4 cm.

Where does 2.54 come from?

The international inch was formally standardized as exactly 2.54 cm in 1959 by agreement between the US, UK, and other Commonwealth countries, replacing several slightly different national definitions that existed before then.

Worked example: a 175 cm height converts to 175 ÷ 2.54 ≈ 68.9 inches (5 ft 8.9 in). Need feet and inches specifically, or other length/weight/volume units? Try the full Unit Converter.