in to mm Converter
Convert inches to millimeters precisely. 1 in = 25.4 mm (exact).
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Length Converter
Convert length units instantly
1 in = 25.4 mm
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How it works
Base unit: m. Values convert via the base unit for this category.
Formula (scale-only):
mm = in × 25.4That is, multiply by 25.4 to convert in to mm.
Examples
- 1 in = 25.4 mm
- 5 in = 127 mm
Tips
- 1 inch is exactly 2.54 centimeters (defined since 1959).
- The international foot is exactly 0.3048 meters.
Popular conversions
| in | mm |
|---|---|
| 1 | 25.4 |
| 5 | 127 |
| 10 | 254 |
| 100 | 2,540 |
Examples
- 1 in = 25.4 mm
- 2.5 in = 63.5 mm
How to convert
mm = in × 25.4. Multiply the value in in by 25.4 to get mm.
Related conversions
FAQs
How many millimeters in an inch?
Exactly 25.4 mm.
Formula for in to mm?
millimeters = inches × 25.4.
Why 25.4 mm?
By international agreement, 1 inch is 25.4 millimeters.