Plan my flock

Chicken coop size calculator

Tell us who is moving in. You get floor space, run, roost bars, nest boxes, vents, feeder and water space, drawn to scale.

Your flock

Rhode Island Red, Orpington, Rock…
Silkie, Sebright, Serama…
Brahma, Jersey Giant, Cochin…
Do they go outside?

Space rules are per bird, so mixed flocks just add up. Very large breeds have no breed-specific extension figure; we use the large-breed range.

Your coop

18–24sq ft floor

About 5 × 4 ft inside, for 6 birds.

60sq ft of run
4–5 ftof roost bar
2nest boxes
1.8–2.4sq ft of vents
18–24 inof feeder edge
0.3–0.5 galwater a day (0.5–0.7 in heat)

Ranges show where extension guides differ. Go to the top of the range in cold climates or if birds spend long days inside.

The rules behind the numbers

3–4 sq ftCoop floor per standard henOlder tables say 1.5–2 sq ft; newer guides (Virginia Tech 2023, Oregon State) say 3–4. We use the newer, roomier figure.Virginia Cooperative Extension · Poultry Extension · Oregon State University Extension +5 more
10 sq ftOutdoor run per standard henVirginia Cooperative Extension · Poultry Extension · The Old Farmer's/Farmers' Almanac +3 more
8–10 inRoost bar per henVirginia Cooperative Extension · The Old Farmer's/Farmers' Almanac · Utah State University Extension +3 more
18–24 inRoost height above the floorPenn State Extension · University of Maryland Extension · Oregon State University Extension +2 more
1 box per 4Hens per nest boxPenn State Extension · Oregon State University Extension · University of Maryland Extension +4 more
12 × 12 × 12 inNest box size (W × H × D)Penn State Extension · Oregon State University Extension · Utah State University Extension +2 more
1 sq ft per 10Vent area per sq ft of floorA rule of thumb (Farmers' Almanac, citing a Penn State manual); extension guides stress high vents and no drafts on the roost.The Old Farmer's/Farmers' Almanac · Penn State Extension · Oregon State University Extension +3 more
3–4 inFeeder edge per adult birdOregon State University Extension / PNW · Penn State Extension · University of Maryland Extension +2 more
0.05–0.07 galWater per hen per dayUniversity of Kentucky Animal & Food Sciences · Colorado State University Extension · Penn State Extension +2 more
0.5 inHardware cloth meshUtah State University Extension · University of Maryland Extension · University of Kentucky Cooperative Extension +2 more
12 inBury the wire this deepPenn State Extension · Virginia Cooperative Extension · University of Maryland Extension +2 more

Questions

How much space do chickens need?

Plan 3–4 sq ft of coop floor per standard-size hen and about 10 sq ft of outdoor run each. Bantams need less (2–3 sq ft inside) and big breeds like Brahmas more (4–5 sq ft). Birds that never go outside need 8–10 sq ft each indoors.

How big a coop do I need for 6 chickens?

For six standard hens with a run: 18–24 sq ft of coop floor (about 5 × 4 ft), 60 sq ft of run, 4–5 ft of roost bar and 2 nest boxes.

How many nest boxes do chickens need?

One nest box for every 4 hens is the extension-service rule. A standard box is about 12 × 12 × 12 inches, set 18–24 inches off the floor and lower than the roost so hens don't sleep in it.

How much roost space per chicken?

Give each standard hen 8–10 inches of roost bar, 18–24 inches above the floor, with bars about 12 inches apart. A 2 × 2 in bar with rounded edges, flat side up, is comfortable for their feet.

Hardware cloth or chicken wire?

Chicken wire keeps chickens in but does not keep predators out. Use 0.5-inch hardware cloth on runs, windows and vents, bury it about 12 inches deep or apron it out to stop digging, and lock the flock in the coop every night. A fence for free-ranging birds should be at least 6 ft tall.

How much ventilation does a coop need?

A common rule of thumb is about 1 square foot of vent opening for every 10 square feet of floor, placed high up, above the birds’ heads, so moist air escapes without a draft on the roost. Extension guides agree that good ventilation matters more than insulation; the exact ratio is a rule of thumb rather than a measured standard.

Sources

  1. 1Small-scale Poultry Housing (2902-1092)Virginia Cooperative Extension (L. Jacobs, P. Clauer; 2023-04-28)
  2. 2Small Scale Poultry HousingPenn State Extension (P. Clauer; reviewed G. Martin; updated 2026-06-25)
  3. 3Chicken housing (housing requirements)University of Maryland Extension (J. Moyle; updated 2022-05-11; space table cites Clauer 2009)
  4. 4Backyard Flock Tip: Housing and Confinement for the Backyard FlockUniversity of Georgia Cooperative Extension (C. Dunkley; Jan 2010)
  5. 5Space Allowances in Housing for Small and Backyard Poultry FlocksPoultry Extension (poultry.extension.org, land-grant collaboration; USDA NIFA supported)
  6. 6Living on the land: Backyard chicken coop design (EC 1644)Oregon State University Extension (Annala et al.; 2014, reviewed 2023)
  7. 7Selecting the Right Chicken Coop for Your FlockThe Old Farmer's/Farmers' Almanac (L. Steele; updated 2026-07-27)
  8. 8Successfully Raising a Small Flock of Laying ChickensPenn State Extension (P. Clauer; updated 2016-04-22)
  9. 9Want to raise backyard chickens for eggs? 5 things to know firstColorado State University SOURCE (J. DeLoss quoting CSU Extension specialists; 2025-04-10)
  10. 10Housing Backyard ChickensUtah State University Extension (D. Frame; 2008)
  11. 11Management Requirements for Laying FlocksPenn State Extension (P. Clauer; updated 2016-05-17)
  12. 12Management of the Small Flock of Chickens (MF-2390)Kansas State University Research and Extension (R. S. Beyer; May 1999)
  13. 13How to feed your laying hens (PNW 477)Oregon State University Extension / PNW (J. Hermes; 2016, reviewed 2024)
  14. 14Chapter 12 - Introduction (water consumption, Table 12.1)University of Kentucky Animal & Food Sciences
  15. 15Practical Feeding Methods for Small Poultry FlocksColorado State University Extension (H. Enos; Dec 2019; tables adapted from Merck 1967)
  16. 16Backyard & Small Poultry Flock Management Series: Feeding the Laying Hen (ANR-2913)Alabama Cooperative Extension System (Pacheco, Gulizia, Downs; Aug 2022)
  17. 17Feeds and Feeding for Small-scale Egg-production Enterprises (ASC-233)University of Kentucky Cooperative Extension (J. Jacob, T. Pescatore; 2017, issued 1-2018)
  18. 18Is There a Correlation Between Rodents and Backyard Chickens?Utah State University Extension (J. Reese, quoting T. Messmer; 2018-08-24)
  19. 19Predator Control (slide deck)University of Maryland Extension (N. Richards, J. Rhodes)
  20. 20Predator Management for Small-scale Poultry Enterprises in Kentucky (ID-245)University of Kentucky Cooperative Extension (Jacob, Pescatore, Springer; 2017)
  21. 21Chickens and PredatorsColorado State University Extension
  22. 22Identifying and Preventing Poultry Predators in the Mid-Atlantic Region (FS-1132)University of Maryland Extension (Moyle et al.; updated 2022-06-16)

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