Millimeter to Centimeter Converter
Converts millimeter to centimeter (mm to cm) and back. The conversion factor is shown below every result.
0.1
cm
How to Convert Millimeter to Centimeter
cm = mm × 0.1
What Is a Millimeter?
The millimeter (mm), an SI length unit, equals one thousandth of a meter.
What Is a Centimeter?
One hundredth of a meter defines the centimeter (cm), a common SI length unit.
mm = cm × 10
Common Millimeter to Centimeter Reference Points
Real-world reference values for quick sanity checks.
| Item | Millimeter (mm) | Centimeter (approx.) |
|---|---|---|
| A standard pencil diameter (approx.) | 7 mm | 0.7 cm |
| A smartphone thickness (approx.) | 8 mm | 0.8 cm |
| Reference values are illustrative approximations for common items, not measured specifications. | ||
Millimeter to Centimeter Conversion Table
| Millimeter (mm) | Centimeter (cm) |
|---|---|
| 1 mm | 0.1 cm |
| 5 mm | 0.5 cm |
| 10 mm | 1 cm |
| 25 mm | 2.5 cm |
| 50 mm | 5 cm |
| 100 mm | 10 cm |
| 250 mm | 25 cm |
| Source: NIST SP 811, Appendix B (SI decimal prefixes) | |
Frequently Asked Questions
How do I convert millimeters to centimeters?
Divide the millimeter value by 10 (or multiply by 0.1). For example, 45 mm × 0.1 = 4.5 cm.
Is millimeters to centimeters always a factor of 10?
Yes, exactly, since both are decimal (base-10) subdivisions of the meter under the SI prefix system.
Why do some rulers show both mm and cm marks?
Centimeter marks give a quick coarse reading, while the finer millimeter ticks between them allow more precise measurement without needing decimals.
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Recommended
A good measuring tool marked in both mm and cm removes the guesswork at the point of use.