Roof Area Multiplier

Determine how many square feet of roof area a building has by measuring from the ground.

Roof area multiplier.

Or just enter your numbers into this roof pitch degrees. This roof pitch chart will give you your multiplier. If this distance measures 4 inches you have a 4 in 12 pitch. That gives you 5 590 square feet which is the actual area of the surface of the roof.

A roof pitch multiplier also called a roof pitch factor is a number that is multiplied by the area covered by a sloped roof to produce the area of the actual surface of the roof. And for a roof with a slope of 6 12 that number 1 118 is your roof slope multiplier. 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. Now you re ready to price out the materials.

This makes measuring easier knowing that you are able to get the exact measurement of roofs by merely standing on the ground. For multi pitched roofs simply add the areas of all common pitches together by toggling layer visibility from the summed layer identified by the eye symbol at the left of the layers control. Determine how many square feet of roof area a building has by measuring blueprints or plans. 8 inches and you have an 8 in 12 pitch.

For roof slopes expressed as x in 12 rise in run the roof pitch multiplier is determined by finding the square root of rise run 1. On a ladder beside the roof place the level a foot or so up the roof hold it level and measure from the 12 inch mark on the level s bottom straight down to the roof.