Convert Millimeters to Inches

How to use the converter

To convert mm to in enter the value in the field below and select the target unit, the value will be displayed below:

Value:
From:
To:
Decimal places:

=

Conversion Tables

Metric
Kilometer (km)
Meter (m)
Decimeter (dm)
Centimeter (cm)
Millimeter (mm)
Micrometer (µm)
Nanometer (nm)
Angstrom (Å)
Astronomical
Parsec (pc)
Light-year
Astronomical unit (AU)
Light-minute
Light-second
British/American
League
Mile (mi)
Furlong
Chain
Rod (rd)
Yard (yd)
Foot (ft)
Hand
Inch (in)
Line
Thousandth (mil)
Thou (thou)
Nautical
Nautical mile
Fathom

How to perform key conversions involving length measurements

The formulas for conversion are represented below:

Millimeters to Inches Formula

in = mm / 25.4

Example: 30 Millimeters in Inches:

in = mm / 25.4

in = 30 / 25.4

in = 1.1811

Inches to Millimeters Formula

mm = in * 25.4

Example: 1.5 Inches in Millimeters:

mm = in * 25.4

mm = 1.5 * 25.4

mm = 38.1

Frequently asked questions involving length and distance

100 Millimeters are equal to how many Inches

Considering that 1 Millimeter equals 0.03937 Inches, you can use a rule of three to get that 100 Millimeters equal 3.94 Inches.

1 mm - 0.03937 in

100 mm - x

Apply the rule of three and get:

x mm = 3.94 inmm

x = 3.94 inches

100 Inches equals how many Millimeters?

If every 1 Inch we have 25.4 Millimeters, just multiply the number of Inches (100) by 25.4, so you will get that 100 in is equivalent to 2540 mm. Observe the calculation below:

mm = in * 25.4

mm = 100 * 25.4

mm = 2540