What is 40 inches to millimeters? The answer is that 40 inches equals 1016 millimeters.
How to convert 40 inches to mm? We know that one inch is equal to 25.4 millimeters, so to convert 40 inches to millimeters, we must multiply the amount of centimeters by 25.4, which means that 40 inches is equal to 40 inches × 25.4 = 1016 mm.
See also: How to convert 40 mm to inches.