mm to Inches
Convert millimeters to inches and back. Screws, tools and hardware are often specified in inches.
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Common values
Formula
inch = mm × 0.03937007874
A 1/2 inch is 12.7 mm and 3/8 inch is 9.525 mm. Imperial and metric threads do not fit each other.
Frequently asked questions
QHow many inch is 1 mm?
1 mm is 0.0394 inch, and 10 mm is 0.3937 inch. Type any value in the box above to convert instantly.
QAnd how many mm is 1 inch?
1 inch is 25.4 mm. This converter works both ways, so typing in the right box updates the left one.
QWhere is this unit used?
A 1/2 inch is 12.7 mm and 3/8 inch is 9.525 mm. Imperial and metric threads do not fit each other.
Other converters
Traditional units (geun, doe, majigi and so on) vary by region and product.