Inches to mm Converter
1 inch = 25.4 mm exactly. Used in engineering drawings, fastener sizing and screen dimensions.
Formula:1 in = 25.4 mm
Quick conversion table — Inch to Millimeter
0.5 in12.7 mm
1 in25.4 mm
2 in50.8 mm
5 in127 mm
10 in254 mm
20 in508 mm
50 in1,270 mm
100 in2,540 mm
500 in12,700 mm
1,000 in25,400 mm
How to convert in to mm
To convert inches to mm, use the formula: 1 in = 25.4 mm. Simply enter the value you want to convert in the field above and the result appears instantly. You can also type in the result field to reverse the conversion.
All conversions use precise mathematical constants validated against international SI standards (NIST and ISO 80000). Results are accurate to 8 significant figures.
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