How To Figure Roofing Area

To calculate the area of your roof first you ll need to calculate the pitch of it.

How to figure roofing area. Thus a moderate 6 in 12 roof pitch means that the roof rises 6 inches vertically for every 12 horizontal inches it runs. 1 roof square 100 square feet. Multiply the length by the width to arrive at the ground area of the house. The pitch of the roof is the rise over a 12 inch run.

This applies to lengths as well as areas. That gives you 5 590 square feet which is the actual area of the surface of the roof. L 30 feet h 12 feet 30 12 2 180 square feet. Roof pitch area multipliers.

If the house has an irregular shape measure each part separately figure the separate areas and add them together. Now you re ready to price out the materials. First use your measuring tape to measure 12 inches on your large level and make a mark at the 12 inch line. To accurately calculate the area of your roof you must first determine its slope or pitch.

100 1 054 105 4ft 2. Climb to the top of your roof. Depending whether the roof area is measured horizontally possibly from a drawing or photograph a correction factor is necessary to determine the actual area of the roof. Next place your ladder against your house at the gable end.

Take your area result and multiply it by the pitch multiplier or slope correction factor found in the table above to arrive at the roof s surface area. While it is possible to estimate the amount of necessary materials using only the. Both metric and imperial measurement systems are displayed in a popup menu over the results area. Use our roof pitch calculator to find the pitch of your roof.

So if you divide your answer of a product of length times height by two you will get the area of a triangle. For example a 4 12 pitch roof that is 100 square feet. Next multiply the footprint of the roof by the multiplier below for your roof pitch to find the overall roof area. The length l times the height h of a triangle is twice its area a2.

Take the area of the roof s footprint say it s 5 000 square feet and multiply 5 000 by 1 118.