How Many Nesting Boxes Per Hen? Ratios, Sizes and Placement

Nest boxes are the cheapest part of a coop and one of the easiest to get wrong. Too few and hens queue, squabble or lay on the floor. Too many and the spare boxes become a place to sleep, which means dirty eggs. The good news: extension guidance on nest boxes is unusually consistent. This guide covers the ratio, the size, the height, and what to put inside.

The ratio: one box per four to five hens

Almost every extension source lands in the same place:

• University of Minnesota Extension: one nest box per 4 to 5 birds.
• Utah State University Extension: one nest box for each four to five hens.
• Virginia Cooperative Extension: at least one nest for every 4 to 5 females in the flock.
• University of Georgia Extension: one nest box for every four to five hens is adequate.
• Oregon State University Extension: one nest box for about every four birds.
• UC Cooperative Extension: a maximum ratio of 5 birds per nest box.
• University of Maine Cooperative Extension: at least 1 nesting box for every 5 birds.
• University of Kentucky (ASC-241): one box per five hens, with a minimum of two per flock.

Penn State uses a slightly more generous rule: two nests for the first four hens, then one more nest for every four additional hens. For eight hens that gives three boxes, where the one-per-four rule gives two.

How CoopSizer rounds it

The calculator sizes on one box per four hens, rounded up, with a minimum of two. It states the range it chose from: from one box per five hens to the Penn State rule.

Why a minimum of two? With one box, a broody hen who decides to sit can block every other hen from laying there. A second box gives the rest of the flock somewhere to go. Kentucky's urban guide sets the same minimum.

Hens often pile into a favorite box and ignore the others. That is normal. The ratio is about having enough capacity at busy times of day, not about every box being used equally.

Size: about 12 by 12 by 12 inches

For standard laying hens the published sizes agree closely:

If you keep large or heavy breeds, go toward the 15 inch end of the Utah State range. For bantams, 12 inches is plenty.

Height and placement

• Off the floor. Utah State says no less than 18 inches off the floor. Georgia suggests about 2 feet above the ground.
• Lower than the roosts. Chickens like to sleep at the highest point available. If the nest boxes are higher than the roost bars, some hens will sleep in the nests and soil them. Keep the top roost above the nest boxes.
• Dark and quiet. Penn State recommends a dark, secluded spot, off the floor and away from the roosts.
• A perch in front. Utah State suggests an optional landing perch 6 to 8 inches out from the box entrance. Georgia places one about 4 inches in front.
• A sloped roof on top. Oregon State recommends a roof sloped at 45 degrees over the boxes so birds cannot roost on top of them.

Oregon State also suggests a chicken-sized ramp up to the boxes if they are mounted high. For heavy breeds a ramp or a landing perch matters more.

The front lip and bedding

A low board across the front of each box keeps bedding, and eggs, from rolling out. Penn State suggests a 3 to 4 inch lip; Utah State gives 4 to 6 inches for the front panel. Inside, Penn State recommends about 3 inches of pine shavings. Georgia suggests boxes half filled with straw or other clean litter.

Clean bedding is the main way to get clean eggs. Replace it whenever it is soiled, and collect eggs at least once a day, as the Kentucky urban guide recommends.

Outside access: worth it?

Many builders mount the boxes so the back opens to the outside of the coop. You collect eggs without walking in, which helps in a small reach-in coop. If you do this, the lid or door needs a latch a raccoon cannot open, and the seam needs to be tight against rain. See predator proofing for latch advice.

Common nest box problems

• Hens sleeping in nests: nests too high, roosts too low or too short. Check the roost guide.
• Eggs on the floor: too few boxes, boxes too bright, or young hens that have not found them yet. Mount them in a darker corner.
• Dirty eggs: soiled bedding or hens roosting on the boxes. Add a sloped top and change bedding more often.
• Broken or eaten eggs: too little bedding, or eggs left too long. Collect daily.

Meat birds do not need them

Virginia Cooperative Extension notes that meat-type birds do not need nest boxes. If you raise both, size the boxes on the laying hens only.

Putting it together

If you have the wall space, building a third box for eight hens costs very little and puts you on the generous end of the range. The coop calculator gives the box count for any flock size and places the boxes on its floor plan.