Ventilation Calculator

The calculator walks you through four simple steps: entering your attic size, choosing a ventilation ratio, selecting a preferred exhaust system, and reviewing intake and exhaust product recommendations. The results from our roof ventilation calculator show how much net free vent area (NFVA) you need to meet your selected ventilation ratio. The tool translates your attic square footage into real product requirements for both intake and exhaust airflow.

By providing specific ventilation needs in product terms, the calculator makes it easier to choose the right system and stay aligned with building codes and best practices. The results are designed to align with Owens Corning’s ventilation system options, helping you move from calculation to confident selection.

Proper attic ventilation plays a critical role in the long-term health of your home. A balanced system helps remove excess heat and moisture, which can otherwise lead to mold, structural damage, and higher energy bills.

Using an attic ventilation calculator ensures your system meets airflow requirements based on your specific attic size and structure, helping you protect your roof and improve energy efficiency. Pairing this with the right Owens Corning® ventilation products can help you create a Total Protection Roofing System® that helps perform and protect.