Spray Booth CFM Calculator
Booth airflow from cross-draft face velocity.
Enter your values
ⓘ Live results
Results
- Extraction airflow
- 12,600 CFM
- Open face area
- 126 sq ft
- Make-up air needed
- 11,970 CFM
- Heating load at 60 °F rise
- 816,480 BTU/h
- Filter area at 250 FPM
- 50.4 sq ft
Quick answer
Spray booth airflow equals the booth's open face area multiplied by the required face velocity, usually 100 FPM.
CFM = booth face area x face velocity
How to use the Spray Booth CFM Calculator
- 1Measure the booth's open face width and height.
- 2Use the face velocity your local code requires — 100 FPM is common for cross-draft booths.
- 3Provide filtered make-up air close to the extraction rate.
Worked example
Using the values the calculator loads with:
Inputs
- Booth width14 ft
- Booth height9 ft
- Face velocity100 FPM
Results
- Extraction airflow12,600 CFM
- Open face area126 sq ft
- Make-up air needed11,970 CFM
- Heating load at 60 °F rise816,480 BTU/h
- Filter area at 250 FPM50.4 sq ft
Frequently asked questions
What if velocity is too low?
Overspray escapes the booth and finish quality drops; too high and you get dry spray and wasted paint.
Do filters change the fan size?
Filters raise static pressure, so pick a fan that hits the CFM at the booth's actual resistance, not free air.
About this calculator
- Built and reviewed by James Whitfield · How we build and test calculators
- Report an error
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.