Steep roofs measure your house at ground level then add in the roof s overhang for greater accuracy.
How to estimate roof square footage.
Costs can vary widely depending on how complex your roofing structure is type of roofing material overall slope number.
Calculate square footage for a roof by measuring and by performing some basic math equations.
You can use the roofing calculator below to get a rough estimate of roofing costs per square foot depending on the type of roofing material.
If your roof is flat or has no more than a 3 in 12 pitch you can calculate its total square footage by simply multiplying the length by the width.
Multiply the square footage of your roof by 1 to get the 10 percent waste allowance.
Keep in mind that the average size of a roof is 1 700 square feet so your total will likely be 10 higher or lower than this figure.
It will display 3 figures.
The total amount of roofing material you need is 17 300 1 730 19 030 square feet.
The calculator cannot account for complex shapes based on a measurement of square footage alone.
The first step in a free roofing estimate is measuring the roof dimensions.
So you re thinking of reroofing the house yourself and want an estimate for how much roofing material you.
With the area measurement you can learn the approximate cost of a new roof.
Get the square footage of roof and divide it by 100 and it will give the number of squares you need and for every decimal number over 3 buy a bundle to achieve the amount of material.
To conclude the example if your total roofing area is 17 300 square feet your waste allowance would be 17 300 x 1 1 730 square feet.
In cases where a roof has a complex shape such as in the image to the right measuring the dimensions and areas of each part of the roof to calculate total area will result in a more accurate measurement of area.
You will need to express this size in terms of square feet.
To calculate the size of the roof you need to measure the size of the roof as if it were flat account for roof pitch calculate square footage and finally determine how many squares of material are required for the roof the calculator above can handle all of this simply enter the length width and pitch and it will determine the size of the roof in squares.
Low average and high figures for the estimator tool.