Inches to Centimeters
Convert inch to centimeter instantly — type a value and read the result, with the exact formula shown.
Example
1 in = 2.54 cm, 5 in = 12.7 cm, 10 in = 25.4 cm.
How it works
Centimeter = Inch × 2.54. Every value is converted through a single meter base unit using internationally defined conversion factors, so any from/to pair stays consistent.
Good to know
Converting inches to centimeters is one of the most common everyday switches between the imperial and metric systems. You reach for it when a TV or monitor is sized in diagonal inches but you need the cm to check it fits a shelf, when a US clothing pattern or shoe size lists inches and the rest of the world expects cm, or when filling out a passport, visa, or medical form that wants your height in centimeters instead of feet and inches.
The inch is an imperial unit with English roots — historically tied to the width of a thumb — while the centimeter is one-hundredth of a meter, the metric base unit defined by the speed of light. Since 1959 the two have been linked by an exact international agreement: one inch is defined as precisely 2.54 cm, so this isn't an approximation but a fixed legal definition.
For quick mental math, a useful rule of thumb is that every inch is roughly two-and-a-half centimeters, so to estimate, double the inches and add a half of that figure. A foot (12 in) lands almost exactly on 30 cm, which makes a handy anchor for taller measurements.
- Rounding caveat: 1 in = 2.54 cm exactly, but values like 1 cm = 0.3937 in are rounded — never assume the reverse direction is just as clean.
- Common mistake: confusing inches with feet, or forgetting that fractional inches (like 5 1⁄2 in) must be converted to a decimal (5.5 in × 2.54) before multiplying.
Frequently asked questions
How do you convert inch to centimeter?
Multiply the number of inches by 2.54 to get centimeters. For example, 1 in = 2.54 cm.
What is 1 inch in centimeters?
1 inch equals 2.54 centimeters (1 in = 2.54 cm).
How many inches are in 1 centimeter?
There are 0.3937008 inches in 1 centimeter.
Is this converter free and private?
Yes. It runs entirely in your browser, so your inputs never leave your device, there is no sign-up, and it works offline once loaded.
Are the conversions exact?
Conversions use internationally defined factors and are exact where the definitions are exact (for example, 1 inch = 2.54 cm). Displayed results are rounded for readability.
People also ask
What is 6 inches in cm?
6 inches equals 15.24 cm, because 6 × 2.54 = 15.24.
How do I convert my height from inches to centimeters?
First convert your full height to inches (multiply feet by 12 and add the extra inches), then multiply by 2.54. For example, 5 ft 9 in is 69 in, which is 69 × 2.54 = 175.26 cm.
What is 12 inches in centimeters?
12 inches (one foot) equals 30.48 cm, which is why a foot is often rounded to 30 cm.
How many cm is a 55 inch TV?
A 55-inch TV measures about 139.7 cm along its diagonal (55 × 2.54), though the actual width and height are smaller because that figure is the corner-to-corner measurement.
Is 1 inch exactly 2.54 cm?
Yes. Since the 1959 international yard and pound agreement, one inch is defined as exactly 2.54 centimeters, so the conversion is precise rather than rounded.
How do I convert inches to cm without a calculator?
Multiply the inches by 2.5 and then add about 1.6% to the result. For a rough estimate, just multiply by 2.5 — so 10 in is close to 25 cm (the exact value is 25.4 cm).
What is 8.5 x 11 inches in cm?
US Letter paper measures 21.59 cm × 27.94 cm, since 8.5 × 2.54 = 21.59 and 11 × 2.54 = 27.94.
How many centimeters are in 4 inches?
4 inches equals 10.16 cm (4 × 2.54).
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