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 review.

Room Ventilation CFM Calculator: Estimate planning airflow for rooms, offices, classrooms, restaurant support spaces, storage rooms, and gyms from area, ceiling height, target ACH, room use, source condition, and duct path before equipment review. The result organizes product, document, and request details; it does not choose a final model.

Updated 2026-06-25

Area square feet ACH air-change target CFM planning airflow Duct route review

The calculator uses volume times ACH divided by 60.
Final airflow targets may be governed by code, design professional requirements, or project conditions.

CFM = area x ceiling height x ACH / 60.

CFM for room size = area x ceiling height x ACH / 60. The calculation turns room volume and a target air-change rate into a planning airflow for office space ventilation fans, restaurants, storage, or gyms; vent size and fan size still depend on source condition, duct path, pressure, sound, and model data.

Area: Room floor area in square feet.
Height: Ceiling height in feet.
ACH: Target air changes per hour.

Multiply floor area by ceiling height to estimate room volume.
Multiply volume by target ACH to get cubic feet per hour.
Divide by 60 to convert hourly airflow into CFM.

AdjustmentRoom type routes the result toward fresh air, exhaust, or duct fan products.

OutputCreates a planning airflow target for product selection.

BoundaryACH planning does not replace code review, occupancy calculations, outdoor-air design, source control, or fan curve verification.

Fresh air target

Occupied rooms often point CFM toward ERV or fresh-air equipment review.

Capture occupancy and filter expectations.

Exhaust target

Odor, moisture, or heat sources can point the result toward exhaust or inline fans.

Name the source.

Duct path

Duct length, elbows, filters, and termination affect delivered airflow.

Map the installed path.

Product family Fresh Air and ERV Systems Ventilation CFM should be paired with room use, source, and duct path before selecting equipment. Reference Ventilation CFM Chart Match the result with the closest guide, worksheet, or application page. Product documents Datasheet guide Use the result to request current model documents after the product family is clear. Project request Request review Carry the sizing result into product, document, quantity, voltage, and timeline details.

Room condition	Project facts	Equipment family	Review note
Office or classroom	Area, occupancy, ACH or known CFM, noise, filter access	Fresh air and ERV systems	Occupied-room sound and service access matter
Restaurant support	Room list, odor or humidity source, duct path, sound target	ERV, exhaust, inline fans	Room-level numbers matter
Storage or utility	Volume, odor or heat source, discharge route, service access	Inline or cabinet fans	Air path can matter more than floor area
Gym or fitness	Peak occupancy, humidity, odor, fresh-air target	ERV plus dehumidifier review	Ventilation and moisture should be reviewed together

Air Curtain Series

Ventilation Fan Types

Fresh Air Systems

Exhaust Fan Options

Dehumidifier Options

Room Ventilation CFM Calculator

Recommended next step

Fresh air target

Exhaust target

Duct path

Room CFM Matrix