Centimeters to Millimeters
( cm → mm )
Instantly convert centimeters to millimeters. Enter any value below and get an accurate result with the full formula and reference table.
How to Convert Centimeters to Millimeters
To convert centimeters to millimeters, multiply the number of centimeters by 10. This is because the metric system is based on powers of ten: “centi” means one hundredth, and “milli” means one thousandth, so 1 cm = 10 mm.
Step-by-Step Example
Let’s convert 5 centimeters to millimeters:
1. Multiply by 10: 5 × 10 = 50 mm
2. So 5 cm equals 50 millimeters.
For a measurement of 2.5 cm: 2.5 × 10 = 25 mm.
Why 10?
The metric system is designed around powers of ten. The prefix “centi-” means one hundredth (0.01), and “milli-” means one thousandth (0.001). Since 0.01 / 0.001 = 10, there are 10 millimeters in a centimeter. Therefore, to convert cm to mm, you move the decimal point one place to the right.
When You’d Use Each Unit
Centimeters are used for everyday measurements: height, clothing sizes, and small objects. Millimeters are used for very small measurements: engineering tolerances, thicknesses, and fine details. Converting between them is essential for precision work, science, and understanding metric measurements.
Common centimeters values converted to millimeters — typical sizes highlighted.
| Centimeters (cm) | Millimeters (mm) | Approximate |
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