What is 420 millimeters to inches? The answer is that 420 mm equals 16.5354 inches.
How to convert 420 mm to inches? We know that one inch is equal to 25.4 millimeters, so to convert 420 millimeters to inches, we must divide the amount of centimeters by 25.4, which means that 420 millimeters is equal to 420 mm ÷ 25.4 = 16.5354 inches.
See also: How to convert 420 inches to mm.