Roof Estimating Multiplier

Next multiply the footprint of the roof by the multiplier below for your roof pitch to find the overall roof area.

Roof estimating multiplier.

Find the square root of the result. Use our roof pitch calculator to find the pitch of your roof. However the end result may be well worth it as your roofing material is estimated to last up to 50 longer and will require less maintenance. Assuming this is a hip roof we multiply this by 1 1 which gives us roughly 18 squares or 1 800 square feet of the roof surface.

For example a 4 12 pitch roof that is 100 square feet. This is because a steep sloped roof requires a taller chimney and more lumber for framing. The slope of the roof provides the rise and the run to be plugged into the equation. This gives us a 3d roof area of 1 625 sq ft.

A 12 in 12 roof can cost up to 50 more than a 4 in 12 roof. Although there s isn t any standard pitch of a roof used on all kinds of sloped roofs you can determine the range of pitches by using a roof angle calculator and by considering factors like the local climate and roofing materials. 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. Roof pitch refers to the measurement of the slope of a roof and you express this as a ratio.

Just multiply the roof width by roof length and then the result should be multiplied by the use of the pitch multiplier. A roof pitch of 4 in 12 4 12 has a rise of 4 and a run of 12. Accurate roof calculations are achieved using this table and all you need to do is measure the roof width and length and then you are ready to do a roof pitch measurement. The pitch of the roof is the rise over a 12 inch run.

Roof pitch area multipliers. The roof pitch multiplier table is very helpful in giving correct and reliable roof measurements and uses pythagorean theory.