Inches to Centimeters Converter
1 inch = 2.54 centimeters
Conversion formula
centimeters = inches x 2.54
To convert inches to centimeters, multiply by 2.54. This is an exact conversion factor established by international agreement in 1959. One inch is defined as precisely 25.4 millimeters.
Inches to Centimeters Table
| Inches (in) | Centimeters (cm) |
|---|---|
| 0.25 | 0.635 |
| 0.5 | 1.27 |
| 1 | 2.54 |
| 6 | 15.24 |
| 12 | 30.48 |
| 24 | 60.96 |
| 36 | 91.44 |
| 48 | 121.92 |
| 55 | 139.7 |
| 72 | 182.88 |
1 inch in every length unit
| Meters | 0.0254 m |
| Kilometers | 0.0000254 km |
| Centimeters | 2.54 cm |
| Millimeters | 25.4 mm |
| Micrometers | 25,400 um |
| Nanometers | 25,400,000 nm |
| Miles | 0.0000157828 mi |
| Yards | 0.0277778 yd |
| Feet | 0.0833333 ft |
| Nautical Miles | 0.0000137149 nmi |
| Light Years | 2.68478e-18 ly |
About Inches to Centimeters
The inches-to-centimeters conversion is exact: 1 inch equals precisely 2.54 cm. This makes it one of the few conversions with no rounding whatsoever.
This conversion is essential for international shipping, where package dimensions must be in centimeters for most carriers outside the US. A 12 x 10 x 8 inch box measures 30.48 x 25.4 x 20.32 cm.
In the workshop, lumber and hardware dimensions often differ between systems. A 2x4 board (which actually measures 1.5 x 3.5 inches) is 3.81 x 8.89 cm. A quarter-inch drill bit is 6.35 mm.
Screen sizes are advertised in inches globally, but physical dimensions are often listed in centimeters. A 27-inch monitor diagonal is 68.58 cm. A 65-inch TV is 165.1 cm diagonally.
For framing and art, standard US frame sizes like 8 x 10 inches translate to 20.32 x 25.4 cm, while 16 x 20 inches is 40.64 x 50.8 cm.
The quick conversion is simple: multiply inches by 2.5 for an estimate, or by 2.54 for exactness. A foot (12 inches) is 30.48 cm, and a yard (36 inches) is 91.44 cm.
Frequently Asked Questions
How many cm is 1 inch exactly?
1 inch is exactly 2.54 centimeters. This is a precise definition, not a rounded approximation.
How do I convert inches to cm for TV screen size?
Multiply the screen size in inches by 2.54. For example, a 55-inch TV has a 139.7 cm diagonal. The actual screen width depends on the aspect ratio.
What is 6 inches in cm?
6 inches equals 15.24 cm. This is approximately the length of a US dollar bill (6.14 inches or 15.6 cm).
Why is 1 inch exactly 2.54 cm?
The 1959 International Yard and Pound Agreement defined the inch as exactly 25.4 millimeters (2.54 cm). Before this, the US and British inches differed slightly.