Chicken Math - How Big Should Your Coop Be?

We're getting chickens! How big should our coop (or chicken tractor) be? The following "chicken math" is per bird. You can go smaller on your coop and run dimensions of course - these are just "my" chicken math specs. Don't forget – your chickens also need a 'run' (the outdoor space where they can safely walk around and scratch in the dirt (or bedding, etc).

Keep in mind that you can save on space by stacking your raised "coop" over the top / back half of your "run".

  • 5 square feet of space in the henhouse
  • 10 square feet outside
  • 3+ inches of feeder space
  • roost bars 2-4 inches wide for chicken feet to sit on
  • 12+ inches of perch space each so they can jostle a bit for position
  • 15 inches spacing between ladder rungs so birds don't poop on lower birds
  • Roost bars should be higher than nesting boxes
  • Roosts can be anywhere from 1 foot off the ground to 2 feet from the ceiling

Let's say you have 6 chickens. Your dimensions would be:

  • Coop: 4x6 feet
  • Run: 4x12 feet

Let's say you have 16 chickens. Your dimensions would then be:

  • Coop: 8x10 feet
  • Run: 8x20 feet (or 10x18, etc.)
If building a chicken tractor, keep in mind that those are going to get heavy really quickly. I'd use just chicken run dimensions for any and build a smaller enclosed 'bedtime' area into the top portion of your tractor. A-frame designs are great at saving on weight.

We've used the 'A-frame Chicken Tractor' plans from Ana White with reasonable success in the past. The only alterations we made were to remove the ramp and floor from the top section of the A-frame (it didn't seem like the structure was large enough for a second level to be feasible). We instead used the upper space for several roost bars.

Here the tractor is shown closed up tight with clear polycarbonate sheeting panels secured over the summer hardware cloth to keep out winter snow and drafts.

The dimensions were 5x10, and we felt that it comfortably supported 6 chickens.

That's all for now, chicken friends!