Inches to mm Converter
Convert inches to millimeters — or mm back to inches. Includes a fractions-of-an-inch reference table. Click any result to copy it.
mm = inches × 25.4inches = mm ÷ 25.4
Inches
in
Millimeters
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Centimeters
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Feet
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Pixels (96 PPI)
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mm → Inches
mm
Inches
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Inches (Fractions) to mm Table
| Inches | Millimeters |
|---|---|
| 1/16" | 1.588 mm |
| 1/8" | 3.175 mm |
| 3/16" | 4.763 mm |
| 1/4" | 6.35 mm |
| 5/16" | 7.938 mm |
| 3/8" | 9.525 mm |
| 1/2" | 12.7 mm |
| 5/8" | 15.875 mm |
| 3/4" | 19.05 mm |
| 1" | 25.4 mm |
| 1.5" | 38.1 mm |
| 2" | 50.8 mm |
| 3" | 76.2 mm |
| 4" | 101.6 mm |
| 5" | 127 mm |
| 6" | 152.4 mm |
| 12" | 304.8 mm |
Measure in mm or inches at actual size
Use our calibrated screen ruler to verify measurements directly on screen.
Frequently Asked Questions
How many mm is 1 inch?
Exactly 25.4 mm. Since 1959, 1 inch is defined as exactly 25.4 millimeters by international agreement.
How do you convert inches to mm?
Multiply the inch value by 25.4. Formula: mm = inches × 25.4. For example, 3 inches × 25.4 = 76.2 mm.
How many mm is 1/4 inch?
1/4 inch = 6.35 mm. Multiply 0.25 × 25.4 = 6.35 mm.
How many mm is 1/2 inch?
1/2 inch = 12.7 mm. Multiply 0.5 × 25.4 = 12.70 mm.
How many mm is 3/4 inch?
3/4 inch = 19.05 mm. Multiply 0.75 × 25.4 = 19.05 mm.
How many inches is 50 mm?
50 mm ÷ 25.4 = 1.9685 inches (approximately 1 31/32 inches).
How many mm is 6 inches?
6 inches × 25.4 = 152.4 mm. A standard 6-inch ruler is exactly 152.4 mm long.