Inches to Millimeters Converter

Fractional inches such as 3/8″ and 5/16″ are everywhere in US hardware, woodworking and tooling. Multiplying by 25.4 turns any inch measurement, fraction or decimal, into an exact metric size.

Convert Units

Result:

Feet & inches ↔ centimeters

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Select a unit to convert to it.

    How to Convert Inches to Millimeters

    millimeters = inches × 25.4

    For a fraction, divide first to get decimal inches: 3/8 = 0.375, then 0.375 × 25.4 = 9.525 mm.

    Worked Examples

    3/8 inch to mm

    1. 3 ÷ 8 = 0.375 in
    2. 0.375 × 25.4 = 9.525

    3/8 in = 9.525 mm

    1.5 inches to mm

    1. 1.5 × 25.4 = 38.1

    1.5 in = 38.1 mm

    Inches to Millimeters Chart

    Inches to Millimeters conversion table
    Inches Millimeters
    1/64″ 0.3969 mm
    1/32″ 0.7938 mm
    1/16″ 1.5875 mm
    3/32″ 2.3812 mm
    1/8″ 3.175 mm
    5/32″ 3.9688 mm
    3/16″ 4.7625 mm
    7/32″ 5.5562 mm
    1/4″ 6.35 mm
    5/16″ 7.9375 mm
    3/8″ 9.525 mm
    7/16″ 11.1125 mm
    1/2″ 12.7 mm
    9/16″ 14.2875 mm
    5/8″ 15.875 mm
    11/16″ 17.4625 mm
    3/4″ 19.05 mm
    13/16″ 20.6375 mm
    7/8″ 22.225 mm
    15/16″ 23.8125 mm
    1″ 25.4 mm
    1 1/4″ 31.75 mm
    1 1/2″ 38.1 mm
    2″ 50.8 mm
    3″ 76.2 mm
    4″ 101.6 mm

    More Length Conversions

    Going the other way? Use the Millimeters to Inches converter, or the Distance & Length Converter for every length unit, with unit definitions and history.

    Last reviewed:

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