Quick Answer
1 inch equals 25.4 millimeters. To convert inches to millimeters, multiply the value by this factor.
Key Facts
- Reverse: 1 millimeter = 0.0393701 inches.
Inches to Millimeters Converter
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1 in = 25.4 millimeters
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Inches to Millimeters Formula
Formula: value × 25.4
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Inches to Millimeters Conversion Table
| Inches (in) | Millimeters (mm) |
|---|---|
| 1 in | 25.4 mm |
| 2 in | 50.8 mm |
| 5 in | 127 mm |
| 10 in | 254 mm |
| 25 in | 635 mm |
| 50 in | 1,270 mm |
| 100 in | 2,540 mm |
| 250 in | 6,350 mm |
| 500 in | 12,700 mm |
| 1,000 in | 25,400 mm |
Frequently Asked Questions
How do I convert inches to millimeters?
Enter the value above and the result appears instantly — the calculation runs entirely in your browser. Formula: value × 25.4.
What is the exact inches to millimeters conversion factor?
1 inch = 25.4 millimeters (shown to 6 significant figures — the converter itself computes at full precision). The reverse factor is 1 millimeter = 0.0393701 inches.
What are some common inches to millimeters conversions?
1 in = 25.4 mm; 10 in = 254 mm; 100 in = 2,540 mm. Use the full conversion table below for more reference values.
Is the inch-to-centimeter conversion exact?
Yes. Since 1959 the inch has been defined internationally as exactly 2.54 centimeters, so conversions between inches, feet, yards, and miles and the metric units are exact, not approximations.
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