When determining the clearance of an A-frame horizontal building, you will start with your leg height. The roof has a standard pitch of 3/12. That means that for every 12 feet of width, the roof will rise 3 feet. To make math easier, that is the same as a ¼ pitch. For every 4 feet over, go up one foot. From the top of the legs to the point at which the roof begins to slope is about six inches on the A-frame carports. Let’s look at an 18 foot wide A-frame carport with a leg height of 6 feet. You will calculate the clearance with the following formula. First, take the leg height of 6 feet and add the 6 inches to the roof where it starts to slope. Now you’re at 6 feet, 6 inches. Next, you will move toward the peak (or center of the building). Count 4 feet in, then move up 1 foot. This brings you 4 feet inward. You have a clearance of 7 feet, 6 inches. Do this until you reach the peak of the building. In this case, it is 9 feet from a leg to the peak. That means the rise will be 2 feet, 4 inches, plus the original 6 inches from the leg, plus the leg height. In total, the peak will have a clearance of about 8 feet, 10 inches. However, you must take the top brace into account, which will lower your peak by a few inches.