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Chicken Coop Size Calculator

Enter how many hens you will keep and how big they are. You get the space the coop and run need, the nesting boxes, the roost bar length and the ventilation to build in.

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Your project

hens

Results

Example job shown. Change the numbers to match yours.

Minimum coop floor area
24 ft²
For example 6.0 × 4.0 ft
What to buy
  • Nesting boxes (1 per 4 hens)2 boxes
  • Rolls of 1/2 in hardware cloth, 4 ft × 50 ft (200 ft² each)The cloth is 4 ft wide, so it is run in two courses (one above the other, overlapped) to cover the 6 ft wall plus the 2 ft apron2 rolls
Outdoor run areaFor example 7.75 × 7.75 ft if square (the hardware cloth below assumes this shape)
60 ft²

Inside the coop

Roost bar length (10 in per hen)
5.0 ft
Ventilation opening (about 1 ft² per bird)
6 ft²

Feed

Feed per day (about 1/4 lb per hen)
1.50 lb

Hardware cloth for the run (1/2 in mesh)

Run perimeter (if the run is square)7.75 ft per side; use your real run shape if it differs
31.0 ft
Hardware cloth: 6 ft walls + 2 ft ground apron, plus 10% wasteFor a 7.75 × 7.75 ft square run. Not the roof; a covered run needs the run area again on top
273 ft²
  • These are common minimums from poultry extension guides. Bigger is better: crowded birds fight, peck and get sick. Predator-proof the run with hardware cloth (not chicken wire) and bury or skirt it, since raccoons, foxes and hawks are the main cause of losses.

Before you buy: round up to whole packs, check the size printed on the label, and add a little spare. Your supplier has the final say.

Blueprint

cooprun6.0 × 4.0 ft7.7 × 7.7 ft

24 ft² coop · 60 ft² run

How this calculator works

Poultry guides give the minimum space per bird: about 3 to 4 square feet inside the coop for standard breeds (2 for bantams, 5 for large breeds), and 8 to 10 square feet per bird in the outdoor run. Nesting boxes are shared at roughly one per four hens, and each bird needs 8 to 12 inches of roost bar. We use 10 inches for standard breeds, 12 for large breeds and 6 for bantams, which are about half the size.

coop area = hens × ft² per birdrun area = hens × run ft² per bird

Worked example: six standard hens need a 24 ft² coop (a 4 × 6 ft house), a 60 ft² run (such as 6 × 10 ft), two nesting boxes, a 5 ft roost bar, and about 6 ft² of ventilation.

Assumptions and sources

The assumptions behind your numbers (waste, sizes, rates) are listed in the notes directly under your results, and they update when you change an input.

The formula and a worked example are shown above, so you can check any result by hand. Read how we calculate and check our numbers. Results are estimates for planning: supplier products vary, so check the size printed on the label.

Tips before you buy

  • Build for more birds than you start with. Most people end up wanting more chickens, and a coop is much easier to size up front than to add on.
  • Ventilation matters more than warmth. Chickens tolerate cold well, but ammonia and damp cause respiratory trouble, so keep high vents open year-round (and draft-free at roost height).
  • Check local rules: many places restrict flock size, roosters, and how close a coop can be to a property line.
  • Raise the coop off the ground, put a roof over the nesting boxes, and build in an easy way to clean the floor.

Quick answers by size

2 chickens8 sq ft coop3 chickens12 sq ft coop4 chickens16 sq ft coop5 chickens20 sq ft coop6 chickens24 sq ft coop8 chickens32 sq ft coop10 chickens40 sq ft coop12 chickens48 sq ft coop15 chickens60 sq ft coop20 chickens80 sq ft coop

Tools & materials for this project

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Nesting box

Frequently asked questions

How many square feet per chicken in a coop?

About 3 to 4 square feet inside the coop for standard-size hens, plus 8 to 10 square feet per bird in an outdoor run. Bantams need less, and large breeds more.

How many nesting boxes do I need?

One box for every 4 or 5 hens is enough. Hens often share their favorite, and having more boxes than needed does not help.

How big should a coop be for 6 chickens?

At least 24 square feet inside (such as 4 × 6 ft) and at least 60 square feet of run, though more is better.

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Estimates only. Results assume standard materials and simple shapes. Supplier products vary, and the final call on quantity, structure and safety is yours. Check your local code and your supplier's guidance before ordering.