The rafters on a 5/12 pitch roof rise 5 inches for every 12 horizontal inches; the rafters on a 6/12 pitch roof rise 6 inches for every 12 horizontal inches.

Your house is x feet wide on the end and has a peak running along the center of the house. You are trying to decide between a 5/12 pitch and a 6/12 pitch for your roof. How much higher will the 6/12 pitch roof be than the 5/12 pitch roof?