Roof Estimating Formulas

Use the following formula which also describes a right triangle.

Roof estimating formulas.

Rafter rise run this formula is from the pythagorean theorem. To get the slope of your roof based on degrees roof rise or x inches per 12 run use our roof pitch calculator. The length l times the height h of a triangle is twice its area a2. Medium slope roof pitch of 6.

The average roof replacement cost is 4 200 6 600 on a 1 600 sq ft. Roof pitch roof pitch is the measurement of a roof s vertical rise divided by its horizontal run. Medium steep slope roof pitch of 9. So if you divide your answer of a product of length times height by two you will get the area of a triangle.

Medium low slope roof pitch of 3 or 4. Otherwise use the table or diagram below. However if you use premium materials such as metal wood shingles clay tile etc the cost of your roof will be at least 9 500 16 000. To accurately calculate the area of your roof you must first determine its slope or pitch.

A roof s pitch is determined by how much it rises vertically for every foot it runs horizontally. Roofing cost can vary widely depending on the size and complexity of your roof type of materials you use as well as your location. 1 roof square 100 square feet. Steep slope roof pitch of 12 or 45 degrees.

It is often compared to slope but is not exactly the same. Thus a moderate 6 in 12 roof pitch means that the roof rises 6 inches vertically for every 12 horizontal inches it runs. Ranch house using asphalt roof shingles. L 30 feet h 12 feet 30 12 2 180 square feet.