What is 12.5 inches to millimeters? The answer is that 12.5 inches equals 317.5 millimeters.
How to convert 12.5 inches to mm? We know that one inch is equal to 25.4 millimeters, so to convert 12.5 inches to millimeters, we must multiply the amount of centimeters by 25.4, which means that 12.5 inches is equal to 12.5 inches × 25.4 = 317.5 mm.
See also: How to convert 12.5 mm to inches.