Inches show up constantly: TV and monitor screen diagonals, wheel sizes, US clothing sizes, technical drawings. But we're used to centimeters. Let's go over how to convert between them.
How many centimeters in an inch
One inch equals 2.54 centimeters. This is a fixed international definition — an exact number.
Conversion formulas
Centimeters to inches:
inches = cm ÷ 2.54
Inches to centimeters:
cm = inches × 2.54
For example, 15 cm ÷ 2.54 ≈ 5.9 inches. And 32 inches × 2.54 = 81.3 cm.
Table of common values
| Inches | Centimeters | Where it's used |
|---|---|---|
| 1″ | 2.54 cm | base value |
| 6″ | 15.2 cm | small items |
| 13″ | 33 cm | laptop screen (diagonal) |
| 15.6″ | 39.6 cm | laptop screen |
| 27″ | 68.6 cm | monitor |
| 55″ | 139.7 cm | TV |
Note: a screen's diagonal in inches is the length across the diagonal, not the width.
Quick conversion online
To avoid keeping 2.54 in your head and juggling fractions, use the length converter — it converts between centimeters, inches, meters, feet, miles, and other units. Enter a value and get all the others at once.
Inches and feet
Feet often appear alongside inches (especially for height): 1 foot = 12 inches = 30.48 cm. A height of "5 feet 9 inches" works out to 5×30.48 + 9×2.54 ≈ 175 cm. The length converter calculates feet too.