Ventilation CFM calculator
Room Ventilation CFM Calculator
Calculate planning CFM from square feet, ceiling height, ACH, room use, source condition, and duct path for offices, classrooms, restaurant support rooms, storage rooms, gyms, and other commercial rooms before equipment selection.
Room Ventilation CFM Calculator: Estimate ventilation CFM from room area, ceiling height, air-change target, room use, source conditions, duct route, filters, and service access. Use the result to compare fresh air, exhaust, inline, and cabinet fan paths; it is not a code design.
Updated 2026-07-06Before you calculate
Room CFM Inputs
The CFM output is a planning target that needs room type, source, duct route, and equipment family context.
- Define the room or zone instead of applying one CFM number across a whole building.
- Enter area, ceiling height, target ACH, room type, and source condition to estimate planning airflow.
- For office space ventilation fans, keep occupancy, filter expectation, sound target, and service access attached to the CFM result.
Result use
Recommended next step
The same CFM can lead to different products depending on whether the room needs fresh air, exhaust, source control, or ducted support.
Carry Forward
Fresh air target
Occupied rooms often point CFM toward ERV or fresh-air equipment selection.
Capture occupancy and filter expectations.Ventilation CFM should be paired with room use, source, and duct path before selecting equipment.