Inches to CM Converter
Free inches to cm converter — multiply by the exact factor 2.54 to turn inches into centimetres instantly, both directions, no signup.
About the Inches to CM Converter
Convert inches to centimetres with the exact international factor: 1 inch = 2.54 cm, so cm = inches × 2.54. Enter a value in inches — decimals like 5.5 work fine — and centimetres appear instantly, with two-way editing.
Inches dominate certain products even in metric countries: TV and monitor diagonals (a 55-inch TV is 139.7 cm), phone screens, wheel rims, jeans waist sizes and paper in US formats. Converting to centimetres tells you whether that 32-inch monitor (81.3 cm) actually fits your desk.
Because the 2.54 factor is exact by definition, every result is mathematically precise — useful for 3D-printing dimensions, PCB layouts, sewing and any workshop task where an accumulated rounding error would show.
How to Use the Inches to CM Converter
- 1Enter a length in inches — for example 12.
- 2Read the centimetre result instantly (12 in = 30.48 cm).
- 3Edit the cm field to convert centimetres back to inches.
- 4Use the table for common values from half an inch to a yard.
Frequently Asked Questions
How many cm is 1 inch?
1 inch is exactly 2.54 cm — a value fixed by international definition in 1959, not an approximation. Half an inch is 1.27 cm and a quarter inch is 0.635 cm.
What is 12 inches in cm?
12 inches (1 foot) is exactly 30.48 cm. Similarly 6 in = 15.24 cm, 24 in = 60.96 cm and 36 in (1 yard) = 91.44 cm.
How many cm is a 55 inch TV?
A 55-inch TV has a 139.7 cm diagonal. Other common sizes: 32 in = 81.3 cm, 43 in = 109.2 cm, 65 in = 165.1 cm. Note the size is the diagonal, not the width — a 55-inch 16:9 screen is about 121.8 cm wide.
What is 5.5 inches in cm?
5.5 inches is 13.97 cm. Phone screens are quoted this way: a 6.1-inch display is 15.49 cm and a 6.7-inch one is 17.02 cm, measured diagonally.
How do I convert inches to cm quickly without a calculator?
Multiply by 2.5 and add a little: 10 in × 2.5 = 25, plus 4% gives 25.4 cm exactly. Or remember anchors: 4 in ≈ 10 cm, 12 in ≈ 30.5 cm, 40 in ≈ 1 m.