Calculating Attic Volume

Measure the length and width of the attic floor space to be ventilated.

Calculating attic volume.

Measure the length of your attic in feet. 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. Calculate or enter the square footage of the attic or area to be vented. 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. Enter the length and width of your attic or ceiling crawl space. Remember the minimum area requirement when using a continuous system is a ratio of 1 300.

1 cubic foot is 12 x 12 144 cubic inches. In order to find the right calculator divide the attic floor space by 300 sq feet. How to calculate the cubic feet of an attic. Click the button to calculate the depth in inches and pounds of total insulation required for this job.

Select if your roof is more flat of peaked. So in our example we will divide the 1 500 square feet by 300. Square footage relates to the floor area only and does not factor in the height of the attic space. Then click on calculate.

Ok so now we know the square footage of the attic area to be ventilated. 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. Make sure to measure in the center at the attic s highest point.

In our case the required 4 vents for the 1200 sq ft house multiply the 144 cubic inches by 4 576 cubic inches. 1 500 square feet 300 5 square feet. Now let s figure out how much ventilation space we need. Input length width and desired r value of the area to be insulated.

Measure the height of your attic in feet. Divide this number by two. Whether you plan on improving the ventilation in your attic or adding energy saving insulation you will need to accurately determine its actual size. Ventilation manufacturers assign an nfa value to the non motorized vents they make.

Use a tape measure to figure out the dimensions of your attic. Measure the width of your attic in feet.