100% free · No sign-up · Instant result
inches to cm
Convert inches to centimeters using the exact factor 1 inch = 2.54 cm.
1 inch equals 2.54 centimeters exactly. This free inches to cm converter uses that defined value, not a rough estimate. Multiply inches by 2.54 to get centimeters. Use it for product dimensions, school work, or any US measurement that must be stated in metric form. Results stay consistent with labels that rely on the international inch definition.
How to convert inches to cm
Multiply inches by 2.54. In short: cm = inches × 2.54.
Example: 8 inches × 2.54 = 20.32 cm. So 8 inches is 20.32 centimeters.
Whole inches and decimals use the same factor. If you start from feet and inches, convert everything to inches first, then multiply once.
inches to cm conversion chart
Common inch values converted to centimeters using the exact 2.54 factor.
| Inches (in) | Centimeters (cm) |
|---|---|
| 1 in | 2.54 cm |
| 2 in | 5.08 cm |
| 3 in | 7.62 cm |
| 4 in | 10.16 cm |
| 5 in | 12.7 cm |
| 10 in | 25.4 cm |
| 15 in | 38.1 cm |
| 20 in | 50.8 cm |
| 25 in | 63.5 cm |
| 30 in | 76.2 cm |
| 40 in | 101.6 cm |
| 50 in | 127 cm |
| 75 in | 190.5 cm |
| 100 in | 254 cm |
The chart is built from the same exact factor as the live tool. No row uses a rounded inch definition.
Common inches to cm conversions
1 inch is exactly 2.54 cm. 12 inches (1 foot) is exactly 30.48 cm.
5 inches is 12.7 cm. 10 inches is 25.4 cm. Those show up often in device and craft sizes.
For height, 70 inches is 177.8 cm. That is a common adult height comparison between US and metric records.
Write the unit next to the number on forms. Clear labels prevent cm and inch mix-ups later.
Screen sizes and photo frames often start in inches in the US. Convert before you order metric mounts or cases.
Why metric length matters next to US inches
US daily life still quotes many sizes in inches. Global product labels, medical charts, and travel rules often use centimeters instead.
Converting inches to cm keeps both systems readable. It is especially useful when a US measurement must match a metric form, packing limit, or international size chart.
If a shipping form wants centimeters only, convert the longest side and enter that single metric value.
Frequently asked questions
How many cm is 1 inch?
1 inch equals exactly 2.54 cm.
How many cm is 5 inches?
5 inches equals 12.7 cm.
How many cm is 12 inches?
12 inches equals 30.48 cm, which is exactly 1 foot.
How many cm is 70 inches?
70 inches equals 177.8 cm.
Is inches to cm an exact conversion?
Yes. The inch is defined as exactly 2.54 centimeters, so the conversion is exact.
More free converters
Convert the other way with cm to inches. Browse more length tools on the length converter page. Also useful: mm to inches.
For the international length definition context, see NIST - SI units for length.