The four life stages and what they eat
- Chick (0–8 weeks). 0.08–0.12 lb/day per chick on starter feed (≥18% crude protein; 20% for the first 2 weeks is common). Chicks should never be free-ranged or supplemented — they need full starter for balanced growth.
- Pullet (8–18 weeks).0.12–0.20 lb/day per pullet on grower feed (~16% protein). Some keepers transition directly to layer feed at 18 weeks; others run a two-week overlap. The calculator assumes you're on grower until point-of-lay.
- Layer (18+ weeks). 0.22–0.33 lb/day per hen on layer feed (~16–18% protein + supplemental calcium). The published baseline. Free-range supplement applies here.
- Molt (annual).0.16–0.28 lb/day per hen during the 6–12 week annual molt window. Lay rate drops sharply, but feed intake doesn't drop proportionally — feather regrowth is protein-intensive and many keepers boost protein to ~20% during molt.
The free-range trap
A common misconception: free-range chickens don't need commercial feed. The math is wrong on two ends. Forage quality varies enormously — lush spring pasture is calorie-rich and protein-adequate; dry late-summer grass is mostly fiber. Calcium availability from foraged sources is essentially zero for most backyard pastures; without supplemental layer feed (which contains calcium carbonate), shells go thin within weeks.
The calculator caps the free-range supplement at 50% as a safety choice — even the most aggressive pasture systems still need commercial feed available 24/7. Treat free-range as a calorie + enrichment supplement, not a replacement for the bag. The 50% cap is HatchMath methodology, flagged as such.
A worked example — 6 standard layers, no free-range
Run the calculator with flock 6, standard breed, layer stage, 0% free-range. The math:
- Layer base: 0.22–0.33 lb/day per hen × 6 hens = 1.32–1.98 lb/day for the flock.
- Weekly: 9–14 lb. Monthly: 40–60 lb.
- Bag recommendation: 50-lb bag (monthly use exceeds 30 lb). Reorder roughly every 25–35 days at the upper-consumption end.
Switch to heavy breed (6 Brahmas) and the daily jumps to 1.5–2.5 lb (about +20% as expected). Switch to 30% free-range supplement and the daily drops to 0.92–1.39 lb — a substantial but not transformative reduction.
Feed waste — the silent multiplier
The calculator outputs feed CONSUMED, not feed PURCHASED. The gap is feed waste, and on most backyard setups it's 20–40% before any deliberate fixes. The waste mechanisms:
- Scratching feed onto the ground.Open trough feeders without an anti-scratch grill — birds use the feeder as a kick-toy. Switch to a feeder with a vertical-sided design (typically PVC or galvanized) that birds can't fling feed from.
- Rain-ruined feed. Feed left exposed in the run after rain molds within 12–24 hours and birds reject it. Cover or move feeders under shelter.
- Rodent theft. Rats and mice can eat 1–2 lb of feed per day from an open feeder. The first sign is consumption climbing without flock changes. Galvanized lidded feeders + night lockup of feeders inside a metal trash can with a tight lid solves it.
- Stale feed.Open feed loses palatability and nutritional value within 4–6 weeks. Don't over-buy.
A flock burning through 40% more than the calculator says is almost always wasting feed, not over-eating. Inspect the feeder first.
Frequently asked
How much feed does one chicken eat per day?
A standard laying hen eats 100–150 grams of feed per day, roughly 0.22–0.33 lb (~0.25 lb / quarter-pound is the commonly-cited figure). Heavy breeds eat 15–25% more; light breeds 5–10% less. Pullets and chicks eat substantially less; molt-stage birds eat ~75–85% of layer baseline.
What protein percentage should the feed be?
Layer ration: 16–18% crude protein. Chick starter: ≥18% (often 20% for the first 2 weeks). Grower (pullet): ~16%. Molt-recovery: ~20%, since feather regrowth is protein-intensive. The calculator outputs feed AMOUNT — confirm formulation by reading the bag tag, not by reformulating yourself.
Can free-range chickens skip commercial feed entirely?
No, and this is one of the more dangerous backyard-flock failure modes. Free-range forage varies enormously by season, pasture quality, and bird density — a flock that ranges on lush spring pasture eats fundamentally differently than the same flock on dry summer grass. Without a balanced ration available, free-ranging birds chronically under-eat protein and calcium, which crashes lay rates and produces thin-shelled eggs. The calculator caps free-range supplement at 50% — even the most aggressive pasture systems still need commercial feed available 24/7. Treat free-range as a calorie supplement, not a replacement.
Is a 25-lb or 50-lb bag better?
50-lb bag wins for cost-per-pound (typically 15–25% cheaper per pound) and reorder cadence — a small backyard flock burns through ~30–60 lb/month, so a 50-lb bag lasts roughly 3–5 weeks. 25-lb bag wins for storage when you don't have a dry rodent-proof container for 50 lb, or for very small flocks (1–3 birds) where 50 lb sits long enough to lose freshness or attract pests. The calculator picks based on monthly use: under ~30 lb/month → 25-lb bag; above → 50-lb. Open feed loses freshness within 4–6 weeks; don't buy a quarter at a time.
My birds eat way more than the calculator says. Is something wrong?
Probably not. Chickens self-regulate intake reasonably well, and feed waste is real — birds scratch feed onto the ground, kick it out of low-rim feeders, and let rain ruin uncovered open feeders. A flock that's burning through 50% more than the calculator says is almost always wasting feed, not over-eating it. Inspect: covered feeder? Off the ground? Anti-scratching grill on top? Feeder shape designed for poultry (vertical sides, not flat trough)? The fix is feeder hardware, not increasing the order. If the feeder is right and consumption is still high, check for rodents — rats and mice can eat 1–2 lb of feed per day from an open feeder.
How does feed amount change in winter vs summer?
Birds eat slightly more in winter (10–20% more, generating body heat) and slightly less in deep summer heat (panting reduces appetite, plus cooler eating windows). The calculator output is an annual-average figure; real-world consumption flexes seasonally around it. If your year-round average matches the calculator output, your flock is on track — winter spikes and summer dips are expected.
Related
- Coop size + run space calculator →
- Coop ventilation calculator →
- Brooder heat-lamp wattage calculator →
- Methodology + sources →
- About HatchMath →
- Editorial policy →
By Jimmy L Wu. Layer baseline (100–150 g/day, ~0.25 lb/day) anchored on Alabama Cooperative Extension System ANR-2913 and UMN Extension. Life-stage multipliers, breed-class adjustments (light −5–10%, heavy +15–25%), and the 50% free-range supplement cap are HatchMath methodology. Engine logic in lib/poultry/feedAmount.ts. Not veterinary advice — for sick birds or any animal-health emergency, consult an avian or livestock veterinarian, or your county Cooperative Extension office.