What is 4 millimeters to inches? The answer is that 4 mm equals 0.1574 inches.
How to convert 4 mm to inches? We know that one inch is equal to 25.4 millimeters, so to convert 4 millimeters to inches, we must divide the amount of centimeters by 25.4, which means that 4 millimeters is equal to 4 mm ÷ 25.4 = 0.1574 inches.
See also: How to convert 4 inches to mm.