Millimeters ↔ Inches

    Convert between millimeters and inches

    Millimeters ↔ Inches

    Quick Facts

    • •1 inch = 25.4 mm
    • •1 mm = 0.03937 inches
    • •A credit card is about 0.76 mm thick

    Millimeters and Inches

    Millimeters are used for precision measurements in engineering, machining, jewelry, and electronics. One inch equals exactly 25.4 millimeters. This conversion is vital for anyone working with technical drawings or importing parts from countries using different measurement systems.

    How to convert Millimeters to Inches

    To convert millimeters to inches, multiply the number of millimeters by the conversion factor. The exact factor is 0.03937.

    Formula

    Inches = Millimeters × 0.03937

    Worked example

    Convert 10 mm to in: 10 mm = 0.3937 in.

    Millimeters to Inches reference table

    Use this quick lookup for common millimeters to inches values.

    Millimeters (mm)Inches (in)
    1 mm0.0394 in
    2 mm0.0787 in
    5 mm0.1969 in
    10 mm0.3937 in
    20 mm0.7874 in
    25 mm0.9843 in
    50 mm1.9685 in
    75 mm2.9528 in
    100 mm3.937 in
    250 mm9.8425 in

    Frequently asked questions

    What is the formula to convert Millimeters to Inches?

    Multiply the number of millimeters by 0.03937 to get inches. For example, 10 mm equals 0.3937 in.

    How many inches are in 1 millimeter?

    1 mm equals 0.0394 in.

    How do I convert inches back to millimeters?

    Reverse the formula: Millimeters = Inches ÷ 0.03937. For example, 100 in equals 2,540 mm.

    Is this Millimeters to Inches converter accurate?

    Yes. Conversions use the internationally accepted ratio for millimeters and inches and are calculated to 4 decimal places in your browser.

    What is 10 mm in in?

    10 mm equals 0.3937 in.

    This calculator is for educational and reference purposes only. Always verify critical calculations independently.