A 3046 window is 3 feet wide by 4 feet 6 inches tall. The first number in this sizing code gives you the width of the window in feet — in this case, 3 feet. The second number tells you how many inches are added to that amount — in this case, 0 inches. The second two numbers tell you the same information about the height. In this case, the window is 4 feet 6 inches tall, or 54 inches tall.