Screen sizes, tires, wrench and bolt sizes — inches still show up in plenty of places. Here's the exact formula plus a quick way to estimate in your head.
The exact formula
One inch is exactly 2.54cm. Multiply the inch value by 2.54 to get centimeters.
| Inches | Centimeters |
|---|---|
| 1 in | 2.54 cm |
| 13 in (laptop) | 33.02 cm |
| 24 in (monitor) | 60.96 cm |
| 55 in (TV) | 139.7 cm |
A quick mental-math shortcut
Without a calculator, "inches × 2.5" gets you close enough for most purposes. A 24-inch screen becomes 24 × 2.5 = 60cm, which is very close to the real value (60.96cm). For a bit more precision, add roughly 2% on top of that estimate.
Screen sizes are measured diagonally
When a monitor, TV, or laptop is labeled "24 inches" or "55 inches," that's the diagonal measurement, not the width or height. To get the actual width and height, you'd also need to factor in the aspect ratio (like 16:9).
Try it now
FastestUnitConverter's length converter handles inches, centimeters, feet, yards, and miles all at once.
Open the length converter →