How To Figure Roofing Area

A roof s pitch is determined by how much it rises vertically for every foot it runs horizontally.

How to figure roofing area.

For example a 4 12 pitch roof that is 100 square feet. First use your measuring tape to measure 12 inches on your large level and make a mark at the 12 inch line. The pitch of the roof is the rise over a 12 inch run. 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. And that s the number you were looking for. While it is possible to estimate the amount of necessary materials using only the. To accurately calculate the area of your roof you must first determine its slope or pitch.

Next multiply the footprint of the roof by the multiplier below for your roof pitch to find the overall roof area. Given pitch and a horizontal area measurement multiply the horizontal area by a correction factor corresponding to pitch provided in the table below to determine the actual area of the roof to be used in the roofing material calculator. 1 roof square 100 square feet. To calculate the area of your roof first you ll need to calculate the pitch of it.

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

Take the area of the roof s footprint say it s 5 000 square feet and multiply 5 000 by 1 118. Thus a moderate 6 in 12 roof pitch means that the roof rises 6 inches vertically for every 12 horizontal inches it runs. Now you re ready to price out the materials. Both metric and imperial measurement systems are displayed in a popup menu over the results area.

100 1 054 105 4ft 2. Climb to the top of your roof. Multiply the length by the width to arrive at the ground area of the house. Next place your ladder against your house at the gable end.

If the house has an irregular shape measure each part separately figure the separate areas and add them together.