Kitchen Exhaust CFM Calculator
Whole-kitchen ventilation by air changes.
Enter your values
Enter the kitchen length in ft.
Enter the kitchen width in ft.
Enter the ceiling height in ft.
Enter the air changes per hour in ACH.
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 required
- 432 CFM
- Kitchen volume
- 1,728 cu ft
- Make-up air to supply
- 346 CFM
- In m³/h
- 734
Quick answer
Kitchens are normally ventilated at 12–15 air changes per hour on top of the cooking hood's local extraction.
CFM = kitchen volume x ACH / 60
At a glance
| What it does | Whole-kitchen ventilation by air changes. |
|---|---|
| Category | HVAC & Airflow |
| Inputs needed | Kitchen length, Kitchen width, Ceiling height, Air changes per hour |
| Main output | Extraction required |
| Formula | CFM = kitchen volume x ACH / 60 |
| Cost | Free — no sign-up, no download |
How to use the Kitchen Exhaust CFM Calculator
- 1Measure the kitchen and enter its dimensions.
- 2Use 12 ACH for domestic kitchens and 15–30 for heavy cooking.
- 3Plan make-up air at about 80% of the extraction rate.
Inputs explained
- Kitchen length(ft)
- Enter the kitchen length in ft.
- Kitchen width(ft)
- Enter the kitchen width in ft.
- Ceiling height(ft)
- Enter the ceiling height in ft.
- Air changes per hour(ACH)
- Enter the air changes per hour in ACH.
Worked example
Using the values the calculator loads with:
Inputs
- Kitchen length16 ft
- Kitchen width12 ft
- Ceiling height9 ft
- Air changes per hour15 ACH
Results
- Extraction required432 CFM
- Kitchen volume1,728 cu ft
- Make-up air to supply346 CFM
- In m³/h734
Frequently asked questions
Is this instead of a hood?
No — hood extraction captures grease at source; whole-room ventilation handles the rest.
What about commercial kitchens?
Commercial hoods are sized per linear foot of hood and appliance duty, often 200–400 CFM per foot.
What do I need to enter into the Kitchen Exhaust CFM Calculator?
Just 4 values: kitchen length, kitchen width, ceiling height, air changes per hour. 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 Kitchen Exhaust CFM Calculator work out the answer?
Kitchens are normally ventilated at 12–15 air changes per hour on top of the cooking hood's local extraction. It applies the formula CFM = kitchen volume x ACH / 60 and shows the working so you can check each step by hand.
Is the Kitchen Exhaust 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.