Convert Inches to Centimeters
Convert inches (in) to centimeters (cm) instantly, and see the exact formula, worked examples, and real-world tips for screens, paper, and clothing sizes.
- Millimeter (mm)25.4
- Centimeter (cm)2.54
- Meter (m)0.0254
- Kilometer (km)0.000025
- Inch (in)1
- Foot (ft)0.083333
- Yard (yd)0.027778
- Mile (mi)0.000016
- Ja/Chuk (자)0.083828
- Chi/Chon (치)0.838284
🔒 Unit conversions are computed in your browser.
The formula for inches to centimeters
To convert inches to centimeters, multiply the number of inches by 2.54. One inch is defined as exactly 2.54 cm, so this isn't a rounded approximation — the conversion is precise. For example, 10 inches equals 10 × 2.54 = 25.4 cm, a 6-inch phone is 15.24 cm, and one foot (12 inches) works out to 30.48 cm. To go the other way, divide centimeters by 2.54, or multiply by 0.3937. The live calculator above handles the decimals for you, so you can check paper, screen, and clothing measurements in seconds.
Where inches actually show up
Inches turn up more often than you'd expect. Screen sizes are the classic case: a 24-inch display is about 60.96 cm, a 27-inch is 68.58 cm, and a 32-inch is 81.28 cm — but remember these numbers describe the diagonal, not the width or height. US Letter paper measures 8.5 × 11 inches, which is 21.59 × 27.94 cm, and a 32-inch jeans waist equals 81.28 cm. When you're buying furniture, clothing, or electronics listed in inches, converting to centimeters first makes it far easier to judge whether something fits your space or your body.
Common conversion mistakes
The most frequent slip is rounding 2.54 down to 2.5. Over short lengths the gap is tiny, but 100 inches at 2.5 gives 250 cm instead of the true 254 cm — a full 4 cm off. For tailoring or machined parts, always use 2.54. Also keep in mind that clothing measured in inches varies by country and brand, so a converted number won't always match the fit exactly; check the size chart too. Unlike temperature (°F and °C), length is a simple proportional relationship, so a single multiplication gives you the exact answer.
Frequently asked questions
Exactly how many centimeters is one inch?
One inch is exactly 2.54 centimeters. This is a defined value, not an estimate, so converting between inches and centimeters carries no rounding error. Multiply any inch measurement by 2.54 and you'll always get the precise result — for instance, 3 inches is 7.62 cm and 5 inches is 12.7 cm.
How many cm is a 27-inch monitor?
27 inches × 2.54 = 68.58 cm. Keep in mind that 68.58 cm is the diagonal measurement. On a 16:9 27-inch monitor the actual width is roughly 59.8 cm and the height about 33.6 cm, so if you're checking whether it fits your desk, measure against the width rather than the diagonal.
How do I convert centimeters back to inches?
Divide centimeters by 2.54 to get inches. For example, 30 cm ÷ 2.54 ≈ 11.81 inches. If you prefer multiplying, use 0.3937 (1 cm ≈ 0.3937 inch) for the same result. Just switch the input direction in the calculator above to see both conversions instantly.