Calculating Attic Volume

Click the button to calculate the depth in inches and pounds of total insulation required for this job.

Calculating attic volume.

Then enter the height at the highest point. Measure the length and width of the attic floor space to be ventilated. Enter the length and width of your attic or ceiling crawl space. Calculate or enter the square footage of the attic or area to be vented.

Use a tape measure to figure out the dimensions of your attic. This calculator will help you estimate hip roof parameters including rafters and roof area person outline anton schedule 2011 08 29 17 53 20 one of users asked us to create calculator which will help him estimate hip roof parameters like rafter s lengths roof rise and roof area. Square footage relates to the floor area only and does not factor in the height of the attic space. Divide this number by two.

Next multiply the 4 square feet into cubic inches. Measure the width of your attic in feet. Ok so now we know the square footage of the attic area to be ventilated. Then click on calculate.

How to calculate the cubic feet of an attic. 1 cubic foot is 12 x 12 144 cubic inches. Attic square footage 2 square inches of exhaust and square inches of intake net free area nfa needed. For heating and air conditioning airflow or for other exhaust fan situations see our airflow calculator.

Select if your roof is more flat of peaked. Measure the height of your attic in feet. 1 500 square feet 300 5 square feet. Nfa is the unobstructed area through which air can pass through a vent usually measured in square inches.

Measure the length of your attic in feet. Whether you plan on improving the ventilation in your attic or adding energy saving insulation you will need to accurately determine its actual size. So in our example we will divide the 1 500 square feet by 300. In order to find the right calculator divide the attic floor space by 300 sq feet.

Input length width and desired r value of the area to be insulated. Let owens corning roofing help you calculate exactly how much ventilation you will need for a healthy and balanced attic with our 4 step ventilation calculator. See how simple that was. In our case the required 4 vents for the 1200 sq ft house multiply the 144 cubic inches by 4 576 cubic inches.

Remember the minimum area requirement when using a continuous system is a ratio of 1 300. Ventilation manufacturers assign an nfa value to the non motorized vents they make.