Chicken Coop Size Calculator
Enter your flock size and housing style — we’ll recommend coop floor area, run space, nesting boxes, and roost lengths.
Your Flock Details
Recommendations
Suggested Coop Footprints
Understanding Chicken Coop Sizing
Getting the right coop size is crucial for your chickens’ health and happiness. Our calculator uses established poultry science and backyard chicken keeping best practices to give you accurate recommendations.
Space Requirements Explained
Coop Space (Indoor) is where your chickens sleep, lay eggs, and seek shelter. The amount needed depends on:
- Free-range chickens (3 sq ft per regular bird): When chickens roam freely most of the day, they only need minimal coop space for sleeping and laying.
- Run access chickens (4 sq ft per regular bird): With an enclosed run, chickens spend more time in the coop area, so they need slightly more space.
- Coop-confined chickens (10 sq ft per regular bird): When weather or predators limit outdoor time, chickens need significantly more indoor space.
Bantam chickens need approximately one-third to half the space of regular chickens due to their smaller size.
Run Space Considerations
The chicken run is their outdoor exercise area. We recommend 10 sq ft per regular bird as a minimum. More space reduces bullying, boredom, and disease transmission. For bantams, 5 sq ft per bird is sufficient.
Roost Space Guidelines
Chickens prefer to sleep on roosts (perches). We recommend:
- Regular chickens: 8-10 inches per bird (we use 9 inches for calculations)
- Bantams: 4-6 inches per bird (we use 5 inches for calculations)
Place roosts higher than nest boxes but allow headroom. Round edges (2×4 with wide side up) are most comfortable.
Nest Box Planning
Nest boxes should be:
- 1 box per 4 hens for free-range and run-access scenarios
- 1 box per 3 hens when confined to coop most of the day
Standard nest box size is 12×12 inches. Place them in the darkest part of the coop, lower than the roosts.
Frequently Asked Questions
While you can build smaller, it often leads to problems: increased aggression, feather picking, higher disease transmission, and stress. Overcrowding is one of the most common mistakes new chicken keepers make.
Calculate based on your largest birds. Smaller chickens will adapt to extra space, but large birds suffer in cramped quarters. If you have significant size variation, consider calculating separately and building to accommodate the larger requirement.
These are general guidelines. In very hot climates, consider extra ventilation and shade. In cold climates, ensure the coop is well-insulated but still ventilated (moisture control is crucial). Adjust space upward by 10-20% for extreme climates.
Height matters for human access and ventilation, but chickens primarily use floor space. Minimum 3-foot ceilings work, but 4-6 feet is better for cleaning and ventilation. Ensure at least 1-foot clearance above the highest roost.
Yes! It’s wise to build 20-30% larger than your current needs. Chicken math is real—most keepers expand their flocks over time. The minimal cost increase during initial construction is much cheaper than building a second coop later.
Meat birds (broilers) have different requirements—they need more space (0.8-1.0 sq ft per bird) because they grow rapidly and are less active. Our calculator focuses on egg-laying breeds and backyard flocks.