Barn Ventilation CFM Calculator
Livestock barn airflow by animal weight.
Reviewed by James Whitfield · How we check our maths
Your values
ⓘ Live results
Results
- Summer airflow
- 13,440 CFM
- Winter airflow
- 168 CFM
- Mild weather (30%)
- 4,032 CFM
- Per animal summer
- 336 CFM
- Total live weight
- 48,000 lb
Quick answer
Barn ventilation is set per animal, from a small winter moisture rate up to a large summer heat-removal rate.
The formula
CFM = animals x rate for season and weight
Worked example
Worked example
Using the values the calculator loads with.
Inputs
- Number of animals40
- Average weight1200 lb
- SpeciesCattle
Result
- Summer airflow13,440 CFM
- Winter airflow168 CFM
- Mild weather (30%)4,032 CFM
- Per animal summer336 CFM
- Total live weight48,000 lb
How to use the Barn Ventilation CFM Calculator
- 1Enter the head count and average animal weight.
- 2Choose the species — poultry needs far more airflow per pound.
- 3Set up staged fans so winter, mild and summer rates are all achievable.
Frequently asked questions
Why three rates?
Winter airflow controls moisture and ammonia; summer airflow removes heat and can be 50-100 times higher.
Natural ventilation?
Curtain-sided barns work well in mild climates but need careful ridge and eave openings.
About this calculator
- Built and reviewed by James Whitfield · How we build and test calculators
- Report an error