Calculating Attic Volume

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.

Calculating attic volume. Measure the height of your attic in feet. Divide this number by two. Click the button to calculate the depth in inches and pounds of total insulation required for this job. Square footage relates to the floor area only and does not factor in the height of the attic space.

Next multiply the 4 square feet into cubic inches. Attic square footage 2 square inches of exhaust and square inches of intake net free area nfa needed. Now let s figure out how much ventilation space we need. 1 500 square feet 300 5 square feet.

So in our example we will divide the 1 500 square feet by 300. Remember the minimum area requirement when using a continuous system is a ratio of 1 300. Calculate or enter the square footage of the attic or area to be vented. How to calculate the cubic feet of an attic.

Measure the length and width of the attic floor space to be ventilated. Select if your roof is more flat of peaked. Measure the length of your attic in feet. In order to find the right calculator divide the attic floor space by 300 sq feet.

Enter the length and width of your attic or ceiling crawl space. Then click on calculate. For heating and air conditioning airflow or for other exhaust fan situations see our airflow calculator. Input length width and desired r value of the area to be insulated.

Then enter the height at the highest point. 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. This calculator is to be used as an estimating tool only. Ventilation manufacturers assign an nfa value to the non motorized vents they make.

Make sure to measure in the center at the attic s highest point. Ok so now we know the square footage of the attic area to be ventilated. Use a tape measure to figure out the dimensions of your attic. 1 cubic foot is 12 x 12 144 cubic inches.

See how simple that was. Nfa is the unobstructed area through which air can pass through a vent usually measured in square inches.