CM to Inches Converter

The formula

1 centimeter = 0.3937 inches, because 1 inch is defined as exactly 2.54 cm and 1 / 2.54 = 0.393700787... The tool rounds that to four decimal places, multiplies your input by it, and shows two decimal places in the result.

Example

30 cm × 0.3937 = 11.811, displayed as 11.81 inches — close to a standard US "12-inch" ruler, which is actually 30.48 cm exactly.

Common sizes

• 2.54 cm = 1.00 in
• 15 cm = 5.91 in (roughly a smartphone's height)
• 21 cm = 8.27 in (A4 paper width)
• 180 cm = 70.87 in (just under 5'11")

Precision note

Because the tool uses 0.3937 rather than the full 0.39370078740157..., results stay accurate to about 5 significant figures — fine for clothing sizes, screen dimensions, or DIY measurements, but not for machining tolerances where you'd want the exact 2.54 cm/in relationship instead.