📏 Length Converter

Millimeters to Centimeters
( mm → cm )

Instantly convert millimeters to centimeters. Enter any value below and get an accurate result with the full formula and reference table.

Converter Tool
mm
cm
Result
10 mm = 1 cm
1
cm
The Formula
cm = mm ÷ 10
1 centimeter = 10 millimeters exactly — the metric system’s simplicity.

How to Convert Millimeters to Centimeters

To convert millimeters to centimeters, divide the number of millimeters 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 25 millimeters to centimeters:

1. Divide by 10: 25 ÷ 10 = 2.5 cm
2. So 25 mm equals 2.5 centimeters.

For a measurement of 100 mm: 100 ÷ 10 = 10 cm.

Why 10?

The metric system is designed around powers of ten. The prefix “milli-” means one thousandth (0.001), and “centi-” means one hundredth (0.01). Since 0.01 / 0.001 = 10, there are 10 millimeters in a centimeter. Therefore, to convert mm to cm, you move the decimal point one place to the left.

When You’d Use Each Unit

Millimeters are used for very small measurements: engineering tolerances, thicknesses, and fine details. Centimeters are used for everyday measurements: height, clothing sizes, and small objects. Converting between them is essential for precision work, science, and understanding metric measurements.

Conversion Table

Common millimeters values converted to centimeters — typical sizes highlighted.

Millimeters (mm) Centimeters (cm) Approximate
Frequently Asked Questions
How many centimeters are in a millimeter? +
One millimeter is equal to 0.1 centimeters exactly.
How do I convert 5 mm to cm? +
5 ÷ 10 = 0.5 cm.
What is 30 mm in cm? +
30 ÷ 10 = 3 cm.
How many millimeters in a centimeter? +
There are exactly 10 millimeters in one centimeter.
What is 1.5 cm in mm? +
1.5 × 10 = 15 mm.
Can I convert centimeters back to millimeters with this tool? +
Yes! Just type a value into the centimeters field and the millimeters field updates automatically. Or use the ⇄ swap button to switch directions.
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