Roof Slope Equation

All you need is a simple trigonometry equation and a calculator that has a square root button.

Roof slope equation.

In the imperial unit of measurements the slope is expressed with the rise and run. Most people interested in roof pitch are actually measuring the slope which is the most useful measurement when considering roofing material and rainwater. Calculating the roof slope factor is not that difficult. Other than the 45 roof slope which is 12 in 12 none of the standard roof pitches 5 in 12 6 in 12 etc are equal to a whole degree.

The picture below shows the pitch of a 7 12 roof slope meaning that for 12 of horizontal measurement roof run the vertical measurement roof rise is 7. Roof pitch calculator results explained. Slope the slope of a roof is represented as x 12 where x is the number of inches in rise for every 12 inches of run this is very useful information for many purposes especially for roof framing the slope sometimes called pitch is calibrated on speed squares. The table below shows common roof pitches and the equivalent grade degrees and radians for each.

Slope is the correct term for the ratio of vertical to horizontal distance on a particular plane of the roof. If you need to find out the area of the roof such as to purchase roofing knowing and using the factor will assist you greatly in determining the exact square footage. A pitch over 9 12 is considered a steep slope roof between 2 12 and 4 12 is considered a low slope roof and less than 2 12 is considered a flat roof. This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement.

Roof pitch refers to the measurement of the slope of a roof and you express this as a ratio. The following table shows the roof pitch rise in run equivalents for all roof slopes in degrees from 1 to 72. Roof slope pitch rise run area calculation methods. By slope angle formula steepness can be obtained by dividing vertical rise by horizontal span.

The minimum roof pitch for shedding snow is around 30 or a 6 12 or 7 12 slope although this is not a definite as the material of your roof the direction of the snow and wind are some factors that can affect whether or not snow will slide as roofs of as little as 10 have been reported to shed snow. Most roof s have a pitch in the 4 12 to 9 12 range. 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. Here we explain and include examples of simple calculations and also examples of using the tangent function to tell us the roof slope or angle the rise and run of a roof the distance under the ridge to the attic floor and how wide we can build an attic room and still have decent head room.