What is 100 millimeters to inches? The answer is that 100 mm equals 3.937 inches.
How to convert 100 mm to inches? We know that one inch is equal to 25.4 millimeters, so to convert 100 millimeters to inches, we must divide the amount of centimeters by 25.4, which means that 100 millimeters is equal to 100 mm ÷ 25.4 = 3.937 inches.
See also: How to convert 100 inches to mm.