Cm to inches

The exact conversion

Centimeters to inches comes up for height, screen size, furniture, and anything sold with a metric measurement to a US buyer. The inch has been exactly 2.54 centimeters since the 1959 international yard and pound agreement, so the conversion is a division, not an estimate: inches = centimeters ÷ 2.54. Thirty centimeters is 11.81 inches. A meter, 100 centimeters, is 39.37 inches.

The formula used above is in = cm ÷ 2.54. Both boxes stay in step, so you can start from either unit. Results are rounded for display; the factor itself is the legal definition, not a rounded shortcut.

Worked examples

Each line is the same formula with a new starting number. You can match it against the converter by typing the value on the left.

• 2.54 centimeters: 2.54 ÷ 2.54 = 1 inch.
• 30 centimeters: 30 ÷ 2.54 = 11.811 inches.
• 180 centimeters: 180 ÷ 2.54 = 70.8661 inches.

Where the rounding matters

Height is usually wanted in feet and inches, not as a long decimal. Divide the total inches by 12. The whole number is the feet, and the remainder is the inches. One hundred eighty centimeters is 70.87 inches. That is 5 feet, with 10.87 inches left over, because 5 × 12 = 60 and 70.87 − 60 = 10.87. Rounded to the nearest inch, 180 cm is 5 feet 11 inches. Five foot ten is 177.8 cm, so 180 cm is a little taller than 5′10″.

A common shortcut is to multiply centimeters by 0.4. That gives 72 inches for 180 cm, about an inch too high. Dividing by 2.5 is closer: 180 ÷ 2.5 = 72 is still high, because the true divisor is 2.54, and 180 ÷ 2.54 = 70.87. For a doorway, a TV, or a tailoring measurement, use 2.54 and keep one decimal place. The inches-to-cm page runs the same factor in the other direction.

Conversion table: cm to inches