Calculator Inch to Cm

The inch is defined as exactly 2.54 centimeters by international agreement (ASTM / NIST, 1959). That makes the calculator inch to cm math very simple: multiply inches by 2.54. There is no rounding in the conversion factor itself, so every result here is as accurate as your input.

Formula

• Inches → cm: cm = in × 2.54
• cm → Inches: in = cm ÷ 2.54

Inch to cm reference table

Inches	Centimeters	Millimeters	Common Use
1 in	2.54 cm	25.4 mm	Base conversion
2 inch to cm	5.08 cm	50.8 mm	Pipe diameter
3 inch to cm	7.62 cm	76.2 mm	Small screen
4 inch to cm	10.16 cm	101.6 mm	Smartphone width
5 inch to cm	12.7 cm	127 mm	Smartphone height
6 in	15.24 cm	152.4 mm	Ruler length
10 inch to cm	25.4 cm	254 mm	Tablet diagonal
12 inch to cm	30.48 cm	304.8 mm	1 foot
14 inch to cm	35.56 cm	355.6 mm	Laptop diagonal
15 in	38.1 cm	381 mm	Laptop diagonal
17 in	43.18 cm	431.8 mm	Desktop monitor
20 in	50.8 cm	508 mm	Monitor diagonal
24 inch to cm	60.96 cm	609.6 mm	Dual monitor
27 in	68.58 cm	685.8 mm	Monitor / iMac
32 inch to cm	81.28 cm	812.8 mm	Small TV
36 in	91.44 cm	914.4 mm	3 feet / 1 yard
42 inch to cm	106.68 cm	1066.8 mm	Mid-size TV
55 in	139.7 cm	1397 mm	Large TV
65 in	165.1 cm	1651 mm	Large TV
72 in	182.88 cm	1828.8 mm	6 feet

Converting heights

For heights written as feet and inches, first convert everything to inches: (feet × 12) + inches. Then multiply by 2.54. This calculator has a built-in "Add Feet" input so you can skip the arithmetic. Enter 5 ft in the feet field and 8 in the inch field to get 172.72 cm, which is the metric version of 5 ft 8 in.

Inches and the metric system

The international inch is a defined unit: 2.54 cm exactly. Every inch-based measurement you see, from tire rim sizes to TV diagonals to bolt lengths, can be converted to metric with no loss of precision. Centimeters are widely used for body measurements (height, waist, chest), clothing sizes, and European product listings.