A chicken tractor holding layers needs about 12 sq ft of floor per hen, 4 of it covered coop and 8 of it run; a tractor holding meat birds needs about 1.5 sq ft each, moved to fresh grass every day. Enter the bird type, the count and how often you will move it, and the calculator returns the floor area, a footprint to aim for, and which of our two tractors, if either, can carry the flock.
The two numbers differ eightfold because the job differs. Layers live in a tractor for years and need room to perch, nest and scratch. Meat birds live in it for six to nine weeks and the pen is a moving feed-and-shade station.
Layers: the 4 plus 8 rule
For laying hens the calculator uses 4 sq ft of covered coop floor and 8 of run per bird. The 4 is our own design default, not a published standard. The 8 comes from Penn State Extension’s housing table, which lists 8 sq ft outdoors for laying hens and 10 for large chickens, with 1.5 and 2 sq ft indoors. Oregon State’s EC 1644 is more generous indoors, at 3 sq ft per bird when there is a run.
Six hens therefore come out at 24 sq ft of coop and 48 of run. That is a floor area of 72 sq ft, and it is bigger than anything we sell as a tractor. Our 6x10 A-frame has 19 sq ft of coop and 33 of run, rated for 4 to 6 hens: at six birds each hen gets 3.2 sq ft inside and 5.5 outside, under our own default and inside Oregon State’s minimum. A tractor can run tighter than a static coop because the run is fresh grass daily, but no extension service publishes a tractor density for layers, so we will not invent one.
Size on usable floor, not footprint. The 4x8 A-frame covers 32 sq ft of ground but gives 26 sq ft you can use, 10 enclosed and 16 of run. The 6x10 covers 60 and gives 52. Sloped sides eat floor, and the chicken tractor plans guide explains how to read the numbers.
Meat birds: 1.5 sq ft and a move schedule
Penn State Extension’s pastured-broiler guide, written with University of Maine Cooperative Extension, puts the stocking density at 1.5 sq ft per bird on pasture. It describes two common pens. The Salatin-style pen is 10 feet wide, 12 feet long and 2 feet high, 120 sq ft of floor, which holds about 80 birds at that density. The taller A-frame is 5.5 feet wide, 10 feet long and 5.5 feet high, 55 sq ft, which holds about 36.
The same guide ties density to moving. In the first three weeks on pasture the pen moves every two to three days; from week four it moves daily; for Cornish Cross in weeks seven and eight it moves twice a day. Cornish Cross reach a 4 lb carcass by about six weeks, slower breeds need eight to nine. The calculator uses 1.5 by default and offers 2.0 for a lower density if you would rather give the birds more room than extension recommends.
For 25 broilers that is 37.5 sq ft at 1.5 or 50 at 2.0. For 50 broilers it is 75 or 100. Those are floor areas, not designs.
What we sell and what we do not
| Tractor | Coop | Run | Hens | Loaded weight | Movers | Materials | Build |
|---|---|---|---|---|---|---|---|
| 4x8 A-frame | 10 sq ft | 16 sq ft | 2-3 | about 375 lb | one, firm level ground | $675-$875 | 14-20 hrs |
| 6x10 A-frame | 19 sq ft | 33 sq ft | 4-6 | about 583 lb | two | $800-$1,025 | 22-30 hrs |
We do not sell a broiler tractor. Both A-frames are designed for hens, with roost bars and a nest bank, and nothing in them has been sized or tested for meat birds. The 6x10 has 52 usable sq ft, so on paper it clears 25 broilers at 1.5 sq ft. The plan’s weights count hens, shavings, feed and water, not 25 growing birds, and Penn State lists Cornish Cross at roughly 5.25 lb live by week six. That is more than 130 lb of birds added to a tractor that is already two people’s work to move. Treat the arithmetic as arithmetic, not a plan.
For a free look at a different shape, the 4x10 hoop tractor has a free preview page, but it is held while we test the bend and we are not selling it. Our A-frame page compares the family if you are choosing a shape.
Moving it and shading it
The move frequency you enter feeds the schedule above. Daily is 30 moves a month; every two to three days is about 10 to 15. Our 4x8 weighs about 375 lb loaded and takes 33 to 67 lb of push by the plan’s own arithmetic; the 6x10 takes 54 to 108 lb and two people. That is the cost of daily moves, and it is why a heavier tractor is a scheduling decision as much as a size one.
For shade, Texas A&M AgriLife’s specialists say birds need shade all day and cool water out of the sun. Our run plan page asks for at least a third of the run shaded at midday, and a tractor’s covered end is the obvious refuge. The calculator reports that third as a target.