Dairy Barn Ventilation Calculator
Fan airflow for a dairy freestall barn by cow count.
Enter your values
Enter the number of cows you are working with.
Enter the cfm per cow in CFM.
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.
- Total fan airflow needed
- 180,000 CFM
- Fans at 20,000 CFM each
- 9
- Airflow per stall
- 1,200 CFM
Quick answer
Dairy cows in freestall barns are commonly cooled with about 1,000-1,500 CFM of directed airflow per cow in the resting area.
CFM = cows x CFM per cow
At a glance
| What it does | Fan airflow for a dairy freestall barn by cow count. |
|---|---|
| Category | HVAC & Airflow |
| Inputs needed | Number of cows, CFM per cow |
| Main output | Total fan airflow needed |
| Formula | CFM = cows x CFM per cow |
| Cost | Free — no sign-up, no download |
How to use the Dairy Barn Ventilation Calculator
- 1Count the resting/feeding herd size to cool.
- 2Apply 1,000-1,500 CFM per cow for effective heat-stress reduction.
- 3Position fans along the feed line and resting stalls for direct airflow on the cows.
Inputs explained
- Number of cows
- Enter the number of cows you are working with.
- CFM per cow(CFM)
- Enter the cfm per cow in CFM.
Worked example
Using the values the calculator loads with:
Inputs
- Number of cows150
- CFM per cow1200 CFM
Results
- Total fan airflow needed180,000 CFM
- Fans at 20,000 CFM each9
- Airflow per stall1,200 CFM
Frequently asked questions
Why cool cows directly?
Heat stress cuts milk production significantly; direct air movement is more effective than just barn ventilation.
Combine with sprinklers?
Yes — soaking plus airflow (evaporative cooling) is the standard heat-abatement combination.
What do I need to enter into the Dairy Barn Ventilation Calculator?
Just 2 values: number of cows, cfm per cow. 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 Dairy Barn Ventilation Calculator work out the answer?
Dairy cows in freestall barns are commonly cooled with about 1,000-1,500 CFM of directed airflow per cow in the resting area. It applies the formula CFM = cows x CFM per cow and shows the working so you can check each step by hand.
Is the Dairy Barn 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.