How to Convert cm to Inches (With Examples)

Centimeters and inches measure the same thing — length — but they come from two different systems, so converting between them means multiplying or dividing by a fixed number rather than just shifting a decimal point.

The formula

One inch is defined as exactly 2.54 centimeters. That single number is all you need:

• cm to inches: divide by 2.54
• inches to cm: multiply by 2.54

Worked examples

10 cm ÷ 2.54 = 3.94 in. So a 10 cm object is just under 4 inches long.

Going the other way: 6 in × 2.54 = 15.24 cm.

A quick mental-math trick

If you don't need precision, roughly divide centimeters by 2.5 instead of 2.54 — it's close enough for everyday estimates like furniture or luggage dimensions, and much easier to do in your head. For anything that needs to be exact (like a recipe, a manufacturing spec, or a printed document), use the full 2.54 conversion or our cm to inches converter.

Common reference points

A US letter sheet of paper is 21.6 × 27.9 cm, which is 8.5 × 11 inches. A standard credit card is 8.56 cm wide, or 3.37 inches — which is also why it's a handy object to calibrate an on-screen ruler against.