Inch to Centimeter Converter (in to cm)

How to Convert Inches to Centimeters

Converting inches to centimeters is one of the most frequently performed unit conversions in everyday life — whether you are checking a TV screen size, converting your height for an international form, or following a metric sewing pattern. Since one inch equals exactly 2.54 centimeters by international definition, the conversion is straightforward: multiply the inch value by 2.54. Use the converter above for instant results, or follow the formula and examples below.

Step-by-step example — Convert 12 in to centimeters:

Step-by-step example — Convert 5.5 in to centimeters:

What is an Inch and a Centimeter?

Inch (in) is an imperial and US customary unit of length equal to exactly 1/12 of a foot or 2.54 centimeters. Defined by international agreement since 1959, the inch is the standard unit for screen and display sizes (smartphones, monitors, TVs), pipe diameters in US plumbing, tire widths, and small component dimensions across hardware and electronics. It is also the unit used alongside feet for human height in the United States — for example, a person described as 5 feet 11 inches tall. One inch is roughly the width of an adult thumb at the knuckle, making it an intuitive small-scale unit of measurement.

Centimeter (cm) is a metric unit of length equal to one-hundredth of a meter (10⁻² m) or 10 millimeters. The prefix "centi-" means one-hundredth in the SI system. Centimeters are the everyday metric unit for measuring human height (used in nearly every country outside the US), clothing sizes, furniture dimensions, paper sizes (A4 is 21 × 29.7 cm), and body measurements for tailoring. A centimeter is roughly the width of a standard pencil eraser — a small but practical unit that bridges the gap between millimeters and meters in daily measurement. One inch equals exactly 2.54 centimeters.

Inch to Centimeter Quick Reference Chart

Inches (in)	Centimeters (cm)	Common Reference
0.5 in	1.27 cm	Thickness of a standard smartphone
1 in	2.54 cm	Width of an adult thumb (approx.)
2 in	5.08 cm	Diameter of a golf ball (1.68 in)
4 in	10.16 cm	Standard smartphone screen width
6 in	15.24 cm	Length of a dollar bill
12 in	30.48 cm	One foot / standard ruler length
24 in	60.96 cm	Typical laptop screen diagonal (large)
36 in	91.44 cm	Standard door width (approx.)
55 in	139.7 cm	Popular mid-size TV screen diagonal
72 in	182.88 cm	6 feet — tall adult male height

Real World Uses of Inch to Centimeter Conversion

• Screen & Display Sizes: TVs, computer monitors, laptops, tablets, and smartphones are universally advertised with diagonal screen sizes in inches — even in countries that otherwise use metric. However, product specification sheets, packaging dimensions, and mounting hardware measurements in most countries outside the US are listed in centimeters. Consumers and retailers convert in to cm when comparing screen sizes internationally, calculating shelf or wall mount space, or verifying that a TV advertised as 65 inches will fit within a 170 cm entertainment unit.
• Clothing & Shoe Sizing: US clothing measurements — chest width, waist, inseam, and sleeve length — are expressed in inches on garment labels and size charts, while the same measurements appear in centimeters on European, Asian, and international size charts. Shoppers and fashion buyers convert inches to centimeters when ordering clothing from international brands or retailers, ensuring accurate fit when the size guide uses centimeter measurements rather than the US inch-based sizing system.
• Height Conversion for International Use: Human height in the United States is expressed in feet and inches (e.g., 5 ft 9 in), while the rest of the world records height in centimeters (e.g., 175 cm). This conversion is needed constantly on international travel documents, medical forms, job applications, sports rosters, and dating profiles. Converting 5 ft 9 in to centimeters — 69 inches × 2.54 = 175.26 cm — is one of the single most searched unit conversions globally.
• Home Improvement & Interior Design: US hardware stores sell lumber, tiles, countertops, and appliances with dimensions listed in inches, while imported furniture, European appliances, and international design plans use centimeters. Homeowners and interior designers convert in to cm when fitting imported kitchen cabinets into inch-measured spaces, hanging European curtain rods in US-standard window frames, or ordering metric-dimensioned tiles to cover a floor measured in inches and feet.

Frequently Asked Questions

How many centimeters are in an inch?

There are exactly 2.54 centimeters in one inch. This is a fixed, internationally defined value: 1 in = 2.54 cm, established by the International Yard and Pound Agreement of 1959.

What is the formula to convert inches to centimeters?

The formula is: cm = in × 2.54. Multiply any inch value by 2.54 to get the equivalent length in centimeters.

What is 1 inch in centimeters?

1 in = 2.54 cm exactly. This is one of the most important and widely memorized unit conversion facts, used daily across medicine, engineering, retail, and international travel.

What is 1 centimeter in inches?

1 cm = 0.3937 in (approximately 0.4 inches). A centimeter is slightly less than half an inch — about the width of a standard pencil eraser.

Is an inch bigger or smaller than a centimeter?

An inch is larger than a centimeter. One inch equals 2.54 centimeters — meaning an inch is about two and a half times the length of a single centimeter.

Why is 1 inch exactly 2.54 cm?

The exact value of 1 inch = 2.54 cm was established by the International Yard and Pound Agreement signed in 1959 by the United States, the United Kingdom, Canada, Australia, New Zealand, and South Africa. Before this agreement, slightly different national definitions of the inch existed. The 2.54 cm value was chosen as a clean, agreed-upon figure that best reconciled existing US and British measurement standards, and it has been the exact legal definition of the inch ever since.

How do I convert height from feet and inches to centimeters?

To convert a height like 5 feet 8 inches to centimeters, first convert the entire height to inches: (5 × 12) + 8 = 68 inches. Then multiply by 2.54: 68 × 2.54 = 172.72 cm. The key step is always converting feet to inches first by multiplying by 12, then applying the in-to-cm formula to the total inch value.