How to use the Inches to Millimeters Converter
- Type the number of inches in the box
- The value in millimeters appears instantly
- Use the table for common values, or switch units to convert anything else
Inches to Millimeters formula
mm = in × 25.4
Example: 0.5 in × 25.4 = 12.7 mm.
💡 1/4 inch is 6.35 mm and 3/8 inch is 9.525 mm.
Inches to Millimeters conversion chart
| Inches | Millimeters |
|---|---|
| 0.125 in | 3.175 mm |
| 0.25 in | 6.35 mm |
| 0.375 in | 9.525 mm |
| 0.5 in | 12.7 mm |
| 0.625 in | 15.875 mm |
| 0.75 in | 19.05 mm |
| 1 in | 25.4 mm |
| 1.5 in | 38.1 mm |
| 2 in | 50.8 mm |
| 3 in | 76.2 mm |
| 4 in | 101.6 mm |
| 6 in | 152.4 mm |
| 10 in | 254 mm |
| 12 in | 304.8 mm |
Frequently asked questions
How do I convert inches to millimeters?
Use the formula mm = in × 25.4. For example, 0.5 in = 12.7 mm.
How many millimeters are in 1 inch?
1 in = 25.4 mm.
Any handy reference points?
1/4 inch is 6.35 mm and 3/8 inch is 9.525 mm.
Is this inches to millimeters converter accurate?
Yes. It uses exact definitions (for example, 1 inch = 2.54 cm and 1 lb = 0.45359237 kg) and shows up to 10 significant digits.
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