Formula
Convert millimeters to inches with:
in = mm / 25.4
Example
25.4 mm = 1 in
millimeters to inches table
Questions
How many inches are in a millimeter?
One millimeter is 0.0393701 inches. Enter any value above to convert instantly.
What is the formula to convert millimeters to inches?
Use in = mm / 25.4. The calculator applies this for every value you type.
Is this conversion exact?
Yes — it uses the standard conversion factor (in = mm / 25.4), rounded to 6 significant digits for display.