How big is 100 mm in inches?

There are 3.93700787 inches in 100 millimeters.

100 millimeters x 0.0393700787 inches/1 millimeter = 3.93700787 inches

1 millimeter = 0.0393700787 inches

Direct Conversion Formula100 mm*

1 in

25.4 mm

=

3.937007874 in