Planning tool · US Extension Standards
Space, perches, nest boxes and feed calculated for your exact flock size. Technical values verified against US Cooperative Extension guidelines and poultry welfare research.
Enter a number between 1 and 500
01 — Space required
Recommended outdoor
43 sq ft/hen — recommended outdoor space
02 — Perches
03 — Nest boxes
04 — Materials
05 — Ventilation required
05 — Feed & water
Source: USDA · Alabama Cooperative Extension
06 — Estimated production
Source: Purina Mills · USDA Chickens & Eggs 2025
08 — Estimated annual cost
Total operating cost ($ US 2025)
Cost per egg: 21¢
Indicative. Feed: $0.45/lb · Bedding: $0.28/lb · Pullet: $18/bird · Construction: $12/sq ft indoor.
09 — Monthly production calendar
Estimated month-by-month production incorporating the natural moult cycle and winter daylight reduction in the northern hemisphere.
Pattern based on: Purina Mills Layer Management Guide · University of Georgia Poultry Science · US climate data
Technical guide
The EU legal minimum is not the welfare optimum. Operating at the legal threshold in a backyard coop generates documented behavioural problems.
The recommended value (43 sq ft/hen) is ideal for backyard flocks. The minimum (10 sq ft/hen) is the absolute limit. Operating below the recommended value produces feather pecking, stress and drops in laying.
US Extension guidelines set 10–12 inches per hen. The 11 inches figure is the validated midpoint. Bars are counted in 4 ft modules — standard timber length — to allow purchase without cuts. Functional height: 18–24 inches.
Alabama Cooperative Extension sets the average at 4.0 oz/hen/day for laying hens. The lower bound (3.5 oz) applies with pasture access. The upper bound (4.5 oz) corresponds to cold climates or larger breeds.
The 70% figure is the average domestic laying rate without artificial light management, documented by Purina Mills. The 85% applies to pure laying breeds (ISA Brown, Leghorn, Lohmann Brown) with active light management. Actual rates depend on flock age and season.
Normal consumption is 0.07 gallons/hen/day. In summer it can reach 0.13 gallons, the maximum documented by Watkins & Tabler (University of Arkansas). Water deprivation for 24 hours reduces laying by 30%.
Ventilation guide
Ammonia above 25 ppm reduces laying rate, damages respiratory mucosa and favours infections. Proper ventilation costs nothing and has a direct impact on production.
For every 10 sq ft of indoor floor area you need at least 1 sq ft of total ventilation opening. The calculator applies the standard conversion of 1 sq ft of ventilation per 10 sq ft of floor area.
Openings must be on opposite walls, with air inlets low (12–24 in) and outlets at the ridge or high on the wall. Natural convection removes ammonia at zero energy cost. Avoid draughts directly onto the perches.
The most common mistake is sealing the coop completely in winter. Relative humidity above 70% causes more problems than cold does. The solution is to reduce openings to a third but keep them always open, with baffles preventing direct airflow onto the birds.
Above 27°C hens reduce feed intake and laying. Above 38°C the risk of mortality is real. In summer maximise openings, provide outdoor shade, cool the water, and if possible install misters in the shade. Water consumption can triple.
Cost analysis
The calculation nobody does before building a coop. Figures are indicative for the US 2025 based on verified market prices. The cost-per-egg figure lets you compare objectively with shop prices.
At current layer pellet prices ($0.40–$0.50/lb), one hen costs approximately $40–$45 per year in feed alone. With access to pasture, home-grown grain or quality kitchen scraps, you can reduce this by 15–25%.
The classic mistake is building a coop too small and expanding it later at twice the cost. Basic DIY construction runs around $10–15/sq ft of indoor space. A coop for 6 hens (24 sq ft indoor) costs roughly $250–300 for the shelter alone.
An annual veterinary check or medical treatments per hen cost $10. Preventive deworming, coccidiosis treatment and basic vaccines are essential. Budgeting $10/hen/year is conservative but realistic.
At organic egg prices ($4.50–$6.00/dozen), 6 hens produce 200–250 eggs on average annually, worth $80–$120. The running cost for 6 hens is around $250–$300/year. Home production is not cheaper than buying, but offers full traceability and certainty about animal welfare.
Moult & seasonality
The annual moult is the reset of the reproductive cycle. A well-fed hen during the moult recovers production in 8–12 weeks. A poorly managed one can take 20. The difference is protein and light management.
The natural moult is triggered by the reduction in daylight hours, typically in September–October in the northern hemisphere. It is a physiological process of feather renewal in which the body prioritises keratin for feathers over egg production. Output drops to 10–30% or stops entirely for 6–12 weeks.
Increase feed protein to 18–20% (vs the standard 16–17%) during the 8 weeks of active moulting. The limiting amino acid is methionine, essential for keratin synthesis. Some keepers add wheat germ or sunflower seeds as a source of methionine and vitamin E.
If the coop has artificial lighting you can prevent moulting by maintaining 14–16 hours of total light (natural + artificial). However, this practice reduces the hens' total productive lifespan. For domestic use without production pressure, allowing moulting is preferable as it ensures a second season of higher quality.
High-production breeds (ISA Brown, Lohmann) have faster but harder moults. Traditional breeds (Sussex, Plymouth Rock) moult gradually and recover more slowly but with better final plumage quality. Marans barely stop laying during the moult, though they reduce to 30–40%.
Breed guide
Production figures vary significantly by breed. These are verified numbers for the six breeds most widely used in Europe and North America for domestic egg production.
The benchmark laying breed, equally suited to backyard settings. Matures at 18–19 weeks and holds high rates through the first year. From year two, production typically drops to 220–250 eggs.
Mediterranean breed with the best feed-to-egg conversion of any common layer. Nervous in confined spaces; needs at least 4 m² of outdoor run to display normal behaviour.
Hybrid developed for commercial production but adapts very well to free-range systems. Consistent brown shell. One of the best feed-conversion ratios among dual-purpose hybrids.
Dual-purpose breed (meat and eggs) especially recommended for families with children. Moderate but steady production over 3–4 years. Handles cold and wet winters well.
One of the oldest domestic breeds in northern Europe. Good forager: reduces feed consumption by 15–20% with pasture access. Robust against common poultry diseases.
Known for its very dark brown (near-chocolate) shell. Low production but highly prized in artisan markets. Excellent wet-weather tolerance; originates from the Atlantic coast of south-west France.
Quick reference
Pre-calculated values for the most common backyard flock sizes.
| Hens | Outdoor rec. (sq ft) | Indoor (sq ft) | Perches (ft) | Nest boxes | Feed/week (lbs) | Water/day (gal) | Eggs/week |
|---|---|---|---|---|---|---|---|
| 3 | 129 | 12 | 2.8 | 1 | 5.3 | 0.21 | 15 |
| 4 | 172 | 16 | 3.7 | 1 | 7 | 0.28 | 20 |
| 6 | 258 | 24 | 5.5 | 2 | 10.5 | 0.42 | 29 |
| 8 | 344 | 32 | 7.3 | 2 | 14 | 0.56 | 39 |
| 10 | 430 | 40 | 9.2 | 3 | 17.5 | 0.7 | 49 |
| 12 | 516 | 48 | 11 | 3 | 21 | 0.84 | 59 |
| 15 | 645 | 60 | 13.8 | 4 | 26.3 | 1.05 | 74 |
| 20 | 860 | 80 | 18.3 | 5 | 35 | 1.4 | 98 |
| 25 | 1075 | 100 | 22.9 | 7 | 43.8 | 1.75 | 123 |
| 30 | 1290 | 120 | 27.5 | 8 | 52.5 | 2.1 | 147 |
Eggs/week at 70% average domestic laying rate · Purina Mills · USDA 2025
Recommended equipment
Technical selection based on your calculator results. Updated prices on Amazon.
The industry standard for predator-proofing chicken runs. 19-gauge galvanized steel mesh with 1/2-inch openings stops raccoons, weasels, and snakes cold. Unlike chicken wire, its welded grid will not unravel over time. Bury the skirt 12 in. underground to deter digging predators.
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Grandpa's Feeder is the gold standard of pest-proof poultry feeders. A weighted step plate opens the lid only when a chicken steps on it, completely excluding wild birds, rats, and mice. Weather-sealed construction keeps feed dry for weeks. Holds up to 20 lb -- perfect for small to medium flocks.
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A clean-water gravity system that eliminates daily refilling. Auto-filling stainless-steel cups release water only when a hen pecks the trigger, preventing algae growth and droppings contamination. BPA-free, food-grade bucket included. Perfect for backyard flocks of 4-12 hens.
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A commercial-grade roll-away nesting box that solves egg-eating hens for good. The angled floor gently guides freshly laid eggs into a padded, covered collection drawer where they stay clean and unbroken. Three spacious compartments suit up to 12 laying hens.
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Manna Pro is Amazon USA's best-reviewed poultry brand. Their layer pellets deliver 16% protein and are enriched with oyster shell calcium for stronger eggshells, vitamins D3 and E for immune health, and natural marigold extract for rich golden yolks. Suitable for hens from 18 weeks.
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Kiln-dried, dust-screened pine shavings that expand to massive volume once opened -- up to 4 cubic feet per bale. The low-dust formula protects the sensitive respiratory tracts of your hens. Natural pine resins provide mild antimicrobial properties. Composts beautifully into rich garden fertilizer.
See price on AmazonFrequently asked questions
Each hen needs at least 43 sq ft of outdoor space for free-range access and 4 sq ft of indoor floor space in the coop. US extension recommendations suggest a minimum of 10 sq ft of outdoor space per bird.
For a family of 4 that eats eggs regularly, 4–6 laying hens produce 15–25 eggs per week — enough to cover regular use plus a surplus to give away.
One nest box per 4 hens. Too few causes queuing, fighting and floor eggs. Too many and hens start roosting in them overnight, soiling the nests and the eggs.
Between 3.5 and 4.5 ounces daily. The verified average under standard domestic conditions is 4.0 oz (Alabama Cooperative Extension). With ample pasture access this can fall to 3 oz. In cold climates or for larger breeds it may exceed 4.5 oz.
Between 18 and 24 inches from the floor. With multiple staggered perches, keep at least 12 inches of horizontal gap between them and 8 inches from the wall to prevent droppings from soiling the bar below.
0.07 gallons (9 fl oz) under normal laying conditions. In summer this can reach 0.13 gallons (17 fl oz). Water deprivation for more than 24 hours reduces laying rate by up to 30% for several weeks.
Depends on breed and management. Pure laying breeds (ISA Brown, Leghorn, Lohmann Brown) produce 280–300 eggs per year with light management. Mixed domestic breeds without light control produce 180–220 eggs annually.
Regulations are determined by local municipal ordinances and zoning laws. Many cities allow a small flock (typically 4-6 hens, no roosters) in backyards. Check with your city clerk or local zoning board before installing.
