Paint Booth Face Velocity Calculator
Cross-draft or downdraft face velocity for a paint booth.
Enter your values
Enter the booth opening width in ft.
Enter the booth opening height in ft.
Choose one of: Cross-draft (100 FPM), Downdraft (75 FPM), Semi-downdraft (60 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.
- Required airflow
- 9,600 CFM
- Face area
- 96 sq ft
- Target velocity
- 100 FPM
- Filter loading margin
- Size fan 15-20% above clean-filter CFM
Quick answer
Cross-draft paint booths are typically designed for 100 FPM face velocity, downdraft booths for 50-100 FPM, per NFPA 33 guidance.
CFM = face area x target velocity
At a glance
| What it does | Cross-draft or downdraft face velocity for a paint booth. |
|---|---|
| Category | HVAC & Airflow |
| Inputs needed | Booth opening width, Booth opening height, Booth type |
| Main output | Required airflow |
| Formula | CFM = face area x target velocity |
| Cost | Free — no sign-up, no download |
How to use the Paint Booth Face Velocity Calculator
- 1Measure the open booth cross-section (width x height).
- 2Choose the booth airflow pattern and its NFPA 33 target velocity.
- 3Add a margin for filter loading over the service life of the media.
Inputs explained
- Booth opening width(ft)
- Enter the booth opening width in ft.
- Booth opening height(ft)
- Enter the booth opening height in ft.
- Booth type
- Choose one of: Cross-draft (100 FPM), Downdraft (75 FPM), Semi-downdraft (60 FPM).
Worked example
Using the values the calculator loads with:
Inputs
- Booth opening width12 ft
- Booth opening height8 ft
- Booth typeCross-draft (100 FPM)
Results
- Required airflow9,600 CFM
- Face area96 sq ft
- Target velocity100 FPM
- Filter loading marginSize fan 15-20% above clean-filter CFM
Frequently asked questions
Why does downdraft need less velocity?
Downdraft uses gravity to help pull overspray down and away from the work, needing less horizontal sweep.
What happens if velocity is too low?
Overspray and solvent vapours are not captured, creating fire and finish-quality risks.
What do I need to enter into the Paint Booth Face Velocity Calculator?
Just 3 values: booth opening width, booth opening height, booth type. 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 Paint Booth Face Velocity Calculator work out the answer?
Cross-draft paint booths are typically designed for 100 FPM face velocity, downdraft booths for 50-100 FPM, per NFPA 33 guidance. It applies the formula CFM = face area x target velocity and shows the working so you can check each step by hand.
Is the Paint Booth Face Velocity 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.