The one number you need: 2.54
Going from inches to centimeters is the friendly direction. You multiply. One inch is exactly 2.54 centimeters, full stop, no rounding involved. The international yard and pound agreement nailed that figure down in 1959, and it’s been the legal definition ever since.
Enter inches, get centimeters back the moment you type. The arithmetic runs locally in your browser, so there’s no upload and no delay waiting on a server.
TV and monitor sizes, finally readable
Here’s where most people land on a page like this. You’re shopping for a screen and the spec is “55 inch,” but your living room is measured in centimeters. The diagonal of a 55-inch TV is 139.7 cm. That tells you the panel’s corner-to-corner span, though the actual width matters more for fitting it into a media unit, so check both dimensions.
A 24-inch monitor? Its diagonal is 60.96 cm. A laptop sold as 15.6 inches measures 39.6 cm across the diagonal. These numbers help when a furniture cutout or a wall mount is spec’d in metric and the device is spec’d in imperial.
Height conversions for forms and profiles
Plenty of websites ask for height in centimeters even if you only know yours in feet and inches. Break your height into total inches first. Someone who’s 5 feet 9 inches is 69 inches tall. Multiply by 2.54 and that’s 175.3 cm. Round to 175 for most forms and you’re fine.
Quick reference for the common heights:
- 5’4” = 64 in = 162.6 cm
- 5’7” = 67 in = 170.2 cm
- 5’10” = 70 in = 177.8 cm
- 6’0” = 72 in = 182.9 cm
- 6’3” = 75 in = 190.5 cm
How to drive it
Type a value in the inches field. The centimeter result appears instantly, no submit button anywhere. Want to flip directions or hop to millimeters and feet instead? The dropdown handles that on the same page. There’s also a reference table underneath for the values people look up most, so a glance often beats typing.
Display rounds to a practical number of decimals. The underlying multiply by 2.54 is exact, so if you need extra precision you can always do it by hand from that ratio.
FAQ
How many cm in an inch?
2.54 centimeters, exactly. No decimals trail off into infinity here. It’s a defined value, not a measured one.
What’s 10 inches in cm?
25.4 cm. Multiply 10 by 2.54. That also happens to be exactly how many millimeters are in an inch, which is a fun coincidence of the metric system.
How do I convert feet and inches to cm?
Convert the whole thing to inches first, then multiply by 2.54. For 5’8”, that’s 68 inches, which gives 172.7 cm. Splitting feet out separately just adds steps.
Is 2.54 an approximation?
It isn’t. Since 1959, one inch is 2.54 cm by international definition. Every inch-to-cm conversion traces back to that exact figure.
What size is a 32-inch TV in cm?
The diagonal is 81.28 cm. Keep in mind that’s the diagonal, so the physical width of the cabinet it needs is smaller than that number.
Does this work offline?
Yep, once the page has loaded. The conversion is plain browser JavaScript, so nothing leaves your device and no connection is needed to crunch the numbers.