Inches to cm
inch-cm• Convert inches and centimeters instantly, both ways. • With a reference table of common monitor and TV sizes.
Monitor and TV sizes
By cm
How to convert inches and centimeters
One inch is exactly 2.54 cm. That is not an approximation — the 1959 international yard and pound agreement defined it that way, so the number is exact. To go from inches to centimeters multiply by 2.54; to go the other way divide by 2.54. The converter above is linked in both directions, so you can type into either box and never think about which way round you are working.
Monitors and TVs are where most people meet inches, and there the figure is the diagonal, not the width. A 55 inch TV has a 139.7 cm diagonal — it is not 139.7 cm wide. On a 16 by 9 screen, a 55 inch panel is roughly 122 cm across and 68 cm tall. If you are checking whether it fits a shelf or a wall, measure against the width, not the diagonal.
Clothing uses inches too: a 30 inch waist is 76.2 cm. Bear in mind that actual measurements vary between brands, so the labelled size and the real circumference often differ by a few centimeters. Bike wheels, laptop screens and golf club lengths are also usually quoted in inches.
Frequently asked questions
How many centimeters is one inch?
One inch is exactly 2.54 cm. That is not an approximation: the 1959 international yard and pound agreement defined it that way. Multiply inches by 2.54 for centimeters, divide centimeters by 2.54 for inches. So 10 inches is 25.4 cm, and 100 cm is about 39.37 inches.
How wide is a 55 inch TV?
The 55 inch figure is the diagonal, 139.7 cm, not the width. On a 16 by 9 panel the actual width is about 121.8 cm and the height about 68.5 cm. A 65 inch set has a 165.1 cm diagonal and is roughly 143.9 cm wide. When you measure the space it has to fit, use the width, not the diagonal.
What is a 30 inch waist in centimeters?
A 30 inch waist is 76.2 cm. A 32 is 81.3 cm and a 34 is 86.4 cm. Bear in mind that jeans vary between brands, so the labelled size and the real circumference often differ by a few centimeters. Use it as a guide and check the detailed measurement chart where one is available.
How much bigger is a 27 inch monitor than a 24 inch?
The diagonals are 68.6 cm and 61.0 cm, a difference of 7.6 cm. On a 16 by 9 panel the widths are about 59.8 cm and 53.1 cm, and the heights about 33.6 cm and 29.9 cm. In other words, three inches of diagonal works out to roughly 6.7 cm of extra width.
What do inches mean on bikes and tires?
On a bicycle, a 26 inch marking is the outer diameter of the wheel, about 66 cm. On a car tire, the 17 or 18 inch figure is the diameter of the wheel rim rather than the whole tire, so two tires with the same inch rating can still have different overall diameters depending on sidewall height. Always check what the inch figure is measuring.
Can I convert shoe sizes with inches?
No. Shoe sizing does not reduce to an inch conversion. Korea and Japan label shoes by foot length in millimeters, but US sizes follow a separate scale rather than a simple division of inches. Use the conversion chart the brand publishes, and note that the same label can mean different lengths across brands.