Elevator Shaft Ventilation Calculator
Vent area for an elevator hoistway per code.
Enter your values
Enter the shaft length in ft.
Enter the shaft width in ft.
Enter the required vent percentage in %.
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.
- Shaft cross-section area
- 56 sq ft
- Required vent area
- 1.96 sq ft
- In sq inches
- 282
Quick answer
Elevator hoistways are commonly required to have permanent venting equal to at least 3.5% of the shaft's cross-sectional area.
Vent area = shaft area x 3.5%
At a glance
| What it does | Vent area for an elevator hoistway per code. |
|---|---|
| Category | HVAC & Airflow |
| Inputs needed | Shaft length, Shaft width, Required vent percentage |
| Main output | Shaft cross-section area |
| Formula | Vent area = shaft area x 3.5% |
| Cost | Free — no sign-up, no download |
How to use the Elevator Shaft Ventilation Calculator
- 1Measure the elevator hoistway's cross-sectional floor area.
- 2Apply the local code percentage, commonly around 3.5% of that area.
- 3Locate the venting at or near the top of the hoistway per code.
Inputs explained
- Shaft length(ft)
- Enter the shaft length in ft.
- Shaft width(ft)
- Enter the shaft width in ft.
- Required vent percentage(%)
- Enter the required vent percentage in %.
Worked example
Using the values the calculator loads with:
Inputs
- Shaft length8 ft
- Shaft width7 ft
- Required vent percentage3.5 %
Results
- Shaft cross-section area56 sq ft
- Required vent area1.96 sq ft
- In sq inches282
Frequently asked questions
Is this for smoke control too?
Basic hoistway venting addresses heat/smoke from a fire in the shaft; dedicated smoke control systems may have separate requirements.
Does every jurisdiction use 3.5%?
Requirements vary by code edition and local amendments — confirm the exact figure with your local building authority.
What do I need to enter into the Elevator Shaft Ventilation Calculator?
Just 3 values: shaft length, shaft width, required vent percentage. 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 Elevator Shaft Ventilation Calculator work out the answer?
Elevator hoistways are commonly required to have permanent venting equal to at least 3.5% of the shaft's cross-sectional area. It applies the formula Vent area = shaft area x 3.5% and shows the working so you can check each step by hand.
Is the Elevator Shaft Ventilation 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.