Spray Booth CFM Calculator
Booth airflow from cross-draft face velocity.
Enter your values
Enter the booth width in ft.
Enter the booth height in ft.
Enter the face velocity in FPM.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- 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
At a glance
| What it does | Booth airflow from cross-draft face velocity. |
|---|---|
| Category | HVAC & Airflow |
| Inputs needed | Booth width, Booth height, Face velocity |
| Main output | Extraction airflow |
| Formula | CFM = booth face area x face velocity |
| Cost | Free — no sign-up, no download |
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.
Inputs explained
- Booth width(ft)
- Enter the booth width in ft.
- Booth height(ft)
- Enter the booth height in ft.
- Face velocity(FPM)
- Enter the face velocity in FPM.
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.
What do I need to enter into the Spray Booth CFM Calculator?
Just 3 values: booth width, booth height, face velocity. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the Spray Booth CFM Calculator work out the answer?
Spray booth airflow equals the booth's open face area multiplied by the required face velocity, usually 100 FPM. It applies the formula CFM = booth face area x face velocity and shows the working so you can check each step by hand.
Is the Spray Booth CFM Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.