Convert inches to mm
1 in = 25.4 mm
1 mm = 0.0393701 in
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How to convert inches to mm
Multiply the value in inches by 25.4 to get mm. As a formula: mm = in × 25.4
Good to know
Multiply inches by 25.4, which is exact. Fractional sizes on spanners, drill bits and screws become awkward decimals: 1/2 in is 12.7 mm and 3/8 in is 9.525 mm.
inches to mm conversion table
| inches (in) | mm (mm) |
|---|---|
| 1/16 in | 1.5875 mm |
| 1/8 in | 3.175 mm |
| 1/4 in | 6.35 mm |
| 3/8 in | 9.525 mm |
| 1/2 in | 12.7 mm |
| 5/8 in | 15 7/8 mm |
| 3/4 in | 19.05 mm |
| 1 in | 25.4 mm |
| 1 1/2 in | 38.1 mm |
| 2 in | 50.8 mm |
| 3 in | 76.2 mm |
| 4 in | 101.6 mm |
| 6 in | 152.4 mm |
| 12 in | 304.8 mm |
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Need other units? The full Length Converter converts between every unit it supports, and the Unit Converters page lists the rest.
inches to mm — questions
How many mm are in 1 in?
1 in = 25.4 mm. Multiply the value in inches by 25.4 to get mm.
How do I convert inches to mm?
Multiply the value in inches by 25.4. For example, 1/4 in × 25.4 = 6.35 mm.
What is 1/4 in in mm?
1/4 in = 6.35 mm.
What is 1/2 in in mm?
1/2 in = 12.7 mm.
What is 2 in in mm?
2 in = 50.8 mm.