About This Centimeters to Millimeters Converter
The centimeter (cm) and millimeter (mm) are both metric length units in the SI system. The relationship is exact and simple: 1 centimeter = 10 millimeters, making this the easiest metric conversion — just move the decimal point one place. 1 mm = 0.1 cm. Both units appear on every ruler and measuring tape, and are the standard for technical drawings, product dimensions, and body measurements worldwide.
This converter also supports meters, inches, feet, and yards. Engineers specifying tolerances in millimeters from centimeter-based blueprints, medical professionals converting measurement readings, jewelers working between ring sizes in mm and product descriptions in cm, and students checking lab measurements all use this conversion daily.
How to Use This Converter
- Enter the centimeter value in the Value field.
- Confirm Centimeter is selected in the From dropdown.
- Select Millimeter in the To dropdown (or any other unit).
- The result and formula appear instantly below.
- Use Swap to convert millimeters back to centimeters, or Reset to return to the default.
Units Covered
| Unit | Symbol | Common Use |
|---|---|---|
| Centimeter | cm | Body measurements, clothing sizes, product dimensions, rulers |
| Millimeter | mm | Engineering tolerances, precision parts, jewelry, rainfall measurements |
| Meter | m | Room dimensions, athletic distances, structural lengths |
| Inch | in | Screen sizes, US product dimensions, hardware specifications |
| Foot | ft | Room heights, construction layouts, human height in US/UK |
| Yard | yd | Fabric and textile measurements, outdoor distances |
Centimeters to Millimeters Conversion Table
| Centimeters [cm] | Millimeters [mm] |
|---|---|
| 1 cm | 10 mm |
| 2 cm | 20 mm |
| 5 cm | 50 mm |
| 10 cm | 100 mm |
| 15 cm | 150 mm |
| 20 cm | 200 mm |
| 25 cm | 250 mm |
| 30 cm | 300 mm |
| 50 cm | 500 mm |
| 100 cm | 1000 mm |
| 150 cm | 1500 mm |
| 200 cm | 2000 mm |
How to Convert Centimeters to Millimeters
To convert centimeters to millimeters, multiply by 10:
Example: Convert 8.5 cm to mm:
To convert millimeters back to centimeters, divide by 10:
Example: Convert 45 mm to cm:
When You Need to Convert Centimeters to Millimeters
Technical drawings and engineering specifications commonly mix centimeters and millimeters. A part drawing may give overall dimensions in centimeters but tolerances in millimeters — a 5 cm shaft with a ±0.5 mm tolerance. Machinists, CAD designers, and quality control engineers convert between the two constantly when reading multi-scale technical documents. CNC machine inputs typically require millimeters, while the design spec may be in centimeters.
Medical imaging and clinical measurements shift between these units regularly. Radiologists report tumor sizes in millimeters — a 15 mm nodule, a 32 mm lesion — while clinicians recording growth over time may note measurements in centimeters for easier comparison. A 1.5 cm mass is 15 mm; a 2.3 cm lymph node is 23 mm. Physicians, nurses, and imaging technicians routinely verify these conversions when transcribing measurement data between systems.
Jewelry and watch manufacturing depend on millimeter precision, but product listings often use centimeters for readability. A watch case diameter of 4.2 cm is 42 mm — the format watchmakers and retailers use. A ring with a 1.6 cm inner diameter is 16 mm, the standard ring sizing format. Jewelers, watch retailers, and customers comparing product specifications across metric formats use this conversion to verify sizing accuracy before purchase or manufacture.