Typography / mm → cm
Convert Millimeters to Centimeters
Convert absolute CSS lengths and desktop-publishing points. Convert Millimeters (mm) to Centimeters (cm). Find the formula, worked examples, unit definitions, and practical guidance below.
Reverse: Centimeters to Millimeters →
How to convert millimeters to centimeters
These use CSS definitions: 1 inch = 96 CSS pixels = 72 points = 6 picas. A CSS pixel is not a physical screen pixel. Relative em, rem, and viewport units need a rendering context and are excluded.
Use x for the value in mm, b for the intermediate value in in, and y for the result in cm.
cm = mm × 0.03937007874015748 ÷ 0.39370078740157477
Worked examples
10 mm ≈ 1 cm
Step 1: (10 × 0.0393700787402) ≈ 0.393700787402 in.
Step 2: 0.393700787402 ÷ 0.393700787402 ≈ 1 cm.20 mm ≈ 2 cm
Step 1: (20 × 0.0393700787402) ≈ 0.787401574803 in.
Step 2: 0.787401574803 ÷ 0.393700787402 ≈ 2 cm.
Results are rounded to 12 significant digits. Converting units does not increase the precision of the original measurement. Very large or small values outside JavaScript’s finite numeric range are rejected.
About Millimeters
Millimeters (mm) measures typography under the conventions above. The base value in in is (x × 0.0393700787402), where x is the numerical value in mm. Factors shown here are rounded for display; calculations use the stored factor.
About Centimeters
Centimeters (cm) measures typography under the conventions above. The base value in in is (x × 0.393700787402), where x is the numerical value in cm. Factors shown here are rounded for display; calculations use the stored factor.
Definitions and sources
Keep these unit conventions consistent when using measurements in construction calculations.
Millimeters to centimeters reference table
| Millimeters (mm) | Centimeters (cm) |
|---|---|
| 1 | 0.1 |
| 5 | 0.5 |
| 10 | 1 |
| 25 | 2.5 |
| 50 | 5 |
| 100 | 10 |
| 1000 | 100 |
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