Chicken Coop Size Calculator

Design a coop that fits your flock using precise space nesting perch and ventilation math with adjustable climate factors breed sizes and roost habits to ensure comfort hygiene predator safety airflow and easy cleaning for year round welfare and steady egg production and stress reduction maximizing daylight access feed zones water points and durability

Enter Your Flock Details

Sets sensible defaults you can override.

Space Per Bird (override as needed)

Example: 1.5 means length is 1.5× width.
Indoor Space Requirements

Accurate coop sizing starts with the flock count and breed body size. Multiply birds by indoor area per bird to find floor space. Adjust upward for cold regions or larger breeds to prevent stress feather pecking moisture and disease risks.

Outdoor Run Sizing

Healthy movement needs adequate run space to disperse pecking pressure and protect ground cover. Multiply birds by run area per bird and consider rotation or deep litter. Add shade and enrichment so birds explore dust bathe and exercise daily safely.

Perches and Nesting

Comfortable roosts reduce crowding and injuries. Multiply birds by perch length per bird and ensure gaps for airflow. Provide one nest box per three to five hens with curtains depth and bedding so eggs remain clean and easy to collect.

Ventilation and Climate

Fresh air removes moisture and ammonia and keeps litter dry. Target vent openings based on floor area and humidity while preventing drafts at perch height. Use adjustable soffit and ridge vents with predator proof mesh for crossflow during every season.

Layout and Maintenance

A practical layout saves labor and supports biosecurity. Separate clean and dirty paths add pop doors and hardware cloth and raise the floor. Include removable trays exterior access to nests and hose friendly finishes so cleaning and inspections remain easy.

How to Use This Calculator

  1. Enter the number of birds and choose the typical breed size and climate for your location.
  2. Review or override the defaults for indoor area per bird, run area per bird, perch length per bird, and hens per nest box to match your goals.
  3. Adjust the safety margin to give extra elbow room for growth, heat waves, or temporary confinement.
  4. Set a preferred aspect ratio to guide suggested length and width dimensions.
  5. Click Calculate to view the required floor space, run size, perch length, nest boxes, ventilation, and suggested layout.

Formulas and Assumptions

  • Indoor floor area: birds × indoor_ft²_per_bird × climate_area_multiplier, then add safety margin.
  • Outdoor run: birds × run_ft²_per_bird × climate_run_multiplier.
  • Nest boxes: ceil(birds ÷ hens_per_nest).
  • Perch length: birds × perch_inches_per_bird.
  • Ventilation: ≥ 1 ft² of vent per 10 ft² floor × climate_vent_multiplier.
  • Suggested L×W: solve for a rectangle with target aspect ratio that matches the indoor floor requirement.

These rules of thumb reflect common backyard practices; always pair space planning with good litter management, ventilation placement, shade, and predator-proof construction.

FAQs

Typical guidance is 3–5 ft² per bird indoors depending on size and climate. This tool lets you choose breed size and adds climate and safety margins to tailor the requirement.
Run size equals birds × run area per bird, with a multiplier for hot climates. More space lowers pecking and protects ground cover. Consider rotating runs or deep litter if space is limited.
Plan roughly one box per 3–5 hens. The calculator uses your hens‑per‑nest value and rounds up to ensure a whole number of boxes.
Use 8–12 inches per bird depending on breed size. The tool totals inches and feet so you can plan roost bars with gaps for airflow and headroom above dropping boards.
A common rule is at least 1 square foot of vent per 10 square feet of floor area. Hot climates benefit from even more intake and exhaust protected with hardware cloth.
Free‑ranging reduces pressure on the run, but indoor space and ventilation still matter for nights, storms, and predators. Keep your indoor targets and adjust run size based on how often birds roam.

Results

Enter your details and press Calculate to see results here.

Tips

  • Keep vents high and protected from wind at roost height to avoid drafts.
  • Place feed and water on cleanable pads and elevate to reduce litter contamination.
  • Use hardware cloth for all openings; avoid simple chicken wire for predator resistance.
  • Consider pop‑door timers and run roofing for weather and predator control.

Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.