The Formula
cm = inches × 2.54
Exactly — the inch is defined as 2.54 cm by international agreement, so there’s no rounding in this direction either. The example above: 10 in × 2.54 = 25.4 cm, almost exactly the height of a sheet of US Letter paper turned sideways.
Fractions of an Inch
American measurements love fractions, and they convert cleanly: 1/8 in = 0.3175 cm, 1/4 in = 0.635 cm, 3/8 in = 0.9525 cm, 1/2 in = 1.27 cm, 3/4 in = 1.905 cm. For plywood, screws, and pipe fittings quoted in fractional inches, convert the whole and fractional parts separately, or type the decimal (3 3/8 in → 3.375) into the converter above.
Where This Conversion Shows Up
Screens: the advertised inch figure is the diagonal — a 15.6 in laptop screen is 39.6 cm corner to corner; a 27 in monitor is 68.6 cm. US products: furniture, frames, and appliances from American stores list inches; a “36-inch” counter height is 91.4 cm. Photography prints: the classic 4 × 6 in print is 10.2 × 15.2 cm — which is why the rest of the world calls it 10×15. Rainfall: US forecasts in inches — 1 in of rain is a soaking 2.54 cm.
Frequently Asked Questions
How many cm is 1 inch?
Exactly 2.54 cm — a definition, not a measurement, fixed since 1959.
What size is a 32-inch TV in cm?
The diagonal is 81.3 cm; the actual width is about 71 cm for a 16:9 panel. Always check the spec sheet’s width/height for furniture fitting — the advertised inches are diagonal only.
How do I enter a measurement like 5 3/4 inches?
Convert the fraction to decimal first: 3/4 = 0.75, so type 5.75. The result, 14.6 cm, carries the full precision.
Is a "foot" just 12 inches?
Yes — 1 ft = 12 in = 30.48 cm exactly. For measurements given in feet and inches, our Length Converter handles feet directly.