インチ cm 変換

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.