🪵 Homestead Sizing Engine
Chicken Coop Size Calculator for 20 Chickens
For homesteaders and small farm egg producers with 20 hens, proper coop ventilation and predator-proofing is critical. Model your specs.
🐔 University Agricultural Standards
Chicken Coop Ventilation & Sizing Calculator
Moisture & Ammonia Prevention
20 Birds
2 Hens6 Hens (Backyard)12 Hens24 Hens40 Hens
Total Ventilation Required
--sq. inches
-- sq. feetHigh Outlets (Gables):-- sq. in.
Low Inlets (Intake):-- sq. in.
Min. Coop Floor Space:-- sq. ft.
Continuous CFM Airflow:-- CFM
🛡️ Predator-Proofing & Airflow Rules
- • Never use chicken wire: Raccoons and weasels tear through chicken wire. Cover all vents with 1/2" 19-gauge welded wire mesh.
- • Keep vents ABOVE roost bars: Ammonia and moisture rise. Vents placed high in the roofline prevent cold drafts blowing on sleeping birds.
Frequently Asked Questions
How much ventilation does a 20-chicken coop need?
A 20-bird coop needs a minimum of 80 sq. ft. of floor space and at least 8 to 10 square feet (1,150+ square inches) of passive ventilation openings.