Inches ↔ Centimeters
Convert between inches and centimeters
Inches ↔ Centimeters
Quick Facts
- •1 inch = 2.54 cm exactly
- •1 foot = 12 inches = 30.48 cm
- •Screen sizes (TVs, monitors) are measured diagonally in inches
What Is an Inch?
An inch is a unit of length in the imperial system, equal to 1/12 of a foot or exactly 2.54 centimeters. It is widely used in the United States, Canada, and the United Kingdom for everyday measurements including screen sizes, paper dimensions, and construction.
What Is a Centimeter?
A centimeter (cm) is a metric unit of length equal to one hundredth of a meter. The metric system is used by the vast majority of countries worldwide and is the standard in science, medicine, and engineering.
How to Convert Inches to Centimeters
To convert inches to centimeters, multiply the number of inches by 2.54. For example, 10 inches × 2.54 = 25.4 cm. To convert centimeters to inches, divide by 2.54.
Understanding the inches ↔ centimeters
The inch has been defined as exactly 2.54 centimetres since 1959, so every inch to centimetre result is exact rather than an approximation. The practical problems are elsewhere: reading fractional inches off a tape measure, and knowing which measurement a product listing actually refers to.
Worked examples
Converting 5 feet 9 inches to centimetres
- 1Convert the feet: 5 × 12 = 60 inches.
- 2Add the remaining inches: 60 + 9 = 69 inches.
- 3Multiply by 2.54: 69 × 2.54 = 175.26 cm.
5 ft 9 in is 175.3 cm.
Converting a 3/8 inch drill bit
- 1Turn the fraction into a decimal: 3 ÷ 8 = 0.375 in.
- 2Multiply by 2.54: 0.375 × 2.54 = 0.9525 cm.
- 3That is 9.5 mm, so a 9.5 mm metric bit is the direct equivalent and 10 mm is the nearest common size.
A 3/8 in bit is 9.53 mm, close to a 10 mm metric bit.
Fractional inches to millimetres and centimetres
Tape measures mark sixteenths. This table converts the marks you will actually read.
| Inches | Decimal in | Millimetres | Centimetres |
|---|---|---|---|
| 1/16 | 0.0625 | 1.59 mm | 0.16 cm |
| 1/8 | 0.125 | 3.18 mm | 0.32 cm |
| 1/4 | 0.25 | 6.35 mm | 0.64 cm |
| 3/8 | 0.375 | 9.53 mm | 0.95 cm |
| 1/2 | 0.5 | 12.70 mm | 1.27 cm |
| 5/8 | 0.625 | 15.88 mm | 1.59 cm |
| 3/4 | 0.75 | 19.05 mm | 1.91 cm |
| 7/8 | 0.875 | 22.23 mm | 2.22 cm |
| 1 | 1.0 | 25.40 mm | 2.54 cm |
Everyday sizes in inches and centimetres
| Item | Inches | Centimetres |
|---|---|---|
| Credit card long edge | 3.37 in | 8.56 cm |
| A4 sheet width | 8.27 in | 21.0 cm |
| Letter sheet width | 8.5 in | 21.6 cm |
| Laptop screen (diagonal) | 13.3 in | 33.8 cm |
| Standard door width | 32 in | 81.3 cm |
| 55 in TV (diagonal) | 55 in | 139.7 cm |
Frequently asked questions
More Length & Distance Tools
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This converter is for reference purposes. Always double-check critical measurements.