Millimeters vs Centimeters
Compare millimeters and centimeters side by side, convert in both directions, and see the exact factor - Length units.
= 0.1 cm
= 10 mm
1 millimeter = 0.1 cm · 1 centimeter = 10 mm
The Millimeters is the smaller unit - the same amount has a smaller number when measured in it.
| Millimeters (mm) | Centimeters (cm) | Centimeters (cm) | Millimeters (mm) |
|---|---|---|---|
| 1 | 0.1 | 1 | 10 |
| 2 | 0.2 | 2 | 20 |
| 5 | 0.5 | 5 | 50 |
| 10 | 1 | 10 | 100 |
| 25 | 2.5 | 25 | 250 |
| 50 | 5 | 50 | 500 |
| 100 | 10 | 100 | 1,000 |
| 250 | 25 | 250 | 2,500 |
| 500 | 50 | 500 | 5,000 |
| 1000 | 100 | 1000 | 10,000 |
Quick Answer
1 millimeter (mm) = 0.1 centimeters (cm), and 1 centimeter = 10 millimeters. Centimeters is the larger unit, so the same physical amount needs a bigger number when measured in millimeters. Convert either way with the live tool below or the dedicated converter pages.
Key Facts
- 1 millimeter (mm) = 0.1 cm
- 1 centimeter (cm) = 10 mm
- Conversion is exact multiplication - no rounding in the factor
- Table below covers common values in both directions
- Dedicated converters: mm→cm and cm→mm pages with live tools
Frequently Asked Questions
Which is bigger, a millimeter or a centimeter?
One millimeter equals 0.1 cm, and one centimeter equals 10 mm. The unit with the larger factor is the physically bigger one.
How do I convert millimeters to centimeters?
Multiply by the factor: value in cm = value in mm × 0.1. Example: 5 mm = 0.5 cm. Reverse: divide by 0.1 (or multiply by 10).
Why are millimeters and centimeters different?
They are two different units measuring the same physical quantity. A millimeter is defined as exactly 0.1 cm, and a centimeter as exactly 10 mm. Because the units differ in size, the number you write down for the same amount depends on which unit you use - the conversion factor itself is exact, with no rounding.
Is there a quick way to convert without a calculator?
Memorize the 1-to factor: 1 millimeter ≈ 0.1 cm. Then multiply. For 2 mm that's ≈ 0.2 cm.
Frequently Asked Questions
One millimeter equals 0.1 cm, and one centimeter equals 10 mm. The unit with the larger factor is the physically bigger one.
Multiply by the factor: value in cm = value in mm × 0.1. Example: 5 mm = 0.5 cm. Reverse: divide by 0.1 (or multiply by 10).
They are two different units measuring the same physical quantity. A millimeter is defined as exactly 0.1 cm, and a centimeter as exactly 10 mm. Because the units differ in size, the number you write down for the same amount depends on which unit you use - the conversion factor itself is exact, with no rounding.
Memorize the 1-to factor: 1 millimeter ≈ 0.1 cm. Then multiply. For 2 mm that's ≈ 0.2 cm.