The short answer — and the biology behind it

Selectively bred laying hens — White Leghorns, Rhode Island Reds, modern hybrids — comfortably produce 250 to 300 eggs in a calendar year, with the very best edging past 300. The ceiling is set by the hen’s own plumbing: forming a single egg takes roughly 24 to 26 hours, so no hen, however prolific, can lay more than one a day.

In practice a hen lays for several days in a row — a run called a “clutch” — then skips a day to let her system reset, because each egg is released a little later than the last until she needs to pause. Stack those clutches across a year and you arrive at that 250–300 figure. A backyard hen with natural daylight and the odd treat usually lands a little lower than a hatchery’s headline number; both are honest, they just describe different conditions.

When do chickens start laying eggs?

Most hens lay their first egg — often a small “pullet egg” — at 16 to 24 weeks of age, with 18 to 22 weeks the usual window. Lightweight production breeds and hybrids (Leghorns, ISA Browns, sex-links) tend to start early, around 16–18 weeks; heavier heritage and dual-purpose breeds (Orpingtons, Wyandottes, Brahmas) can take 24 weeks or more.

Season matters too. A pullet that reaches laying age in autumn, as daylight shrinks, may hold off until spring. The first eggs are typically small and sometimes oddly shaped or soft-shelled; this is normal, and they settle into full-size, regular eggs within a few weeks as her reproductive system finds its rhythm.

The best egg-laying breeds, compared

If eggs are the goal, breed is the single biggest lever you can pull. Broadly, commercial hybrids (ISA Brown, Golden Comet, Lohmann Brown) out-lay everything for the first two years but fade faster; heritage breeds (Australorp, Rhode Island Red, Barred Rock, Sussex) lay a little less each year but keep going for longer. Here’s how the popular layers stack up:

Figures are typical annual ranges in good backyard conditions; individual hens, diet, climate and daylight all shift the numbers.

What colour eggs will they lay?

Shell colour is set by genetics, not diet, and it’s one of the great joys of a mixed flock. White eggs come from Leghorns and other Mediterranean breeds; brown from Rhode Island Reds, Sussex and most hybrids. For something special, Ameraucanas and Araucanas lay blue (the pigment runs all the way through the shell), Easter Eggers lay blue, green or even pink, and Marans and Welsummers lay deep chocolate-brown. An old rule of thumb — white earlobes mean white eggs, red earlobes mean brown — holds surprisingly often, though it isn’t foolproof.

One myth worth retiring: there is no chicken that lays truly black eggs. The striking all-black Ayam Cemani — black feathers, skin, even bones — still lays ordinary cream-coloured eggs. The darkest eggs you can get are the rich chocolate browns of a Marans, not black.

Why aren’t my chickens laying?

A sudden drop in eggs sends every keeper hunting for answers. The usual culprits, roughly in order of likelihood:

Daylight. Hens need about 14–16 hours of light for peak laying, so production naturally slows or stops in winter unless you add artificial light. The annual moult. Once a year, usually in autumn, hens drop and regrow their feathers — an energy-hungry process that pauses laying for several weeks. Age. Birds under ~18 weeks aren’t ready; older hens lay less. Broodiness. A hen determined to hatch eggs stops laying for the 3–8 weeks she sits. Stress. Predators, a new flock member, a move, extreme heat or a fright can all shut laying down. Nutrition. Too little protein or calcium — often from too many treats diluting their feed — quickly cuts output. And don’t rule out hidden nests: free-ranging hens sometimes lay in a secret spot rather than stopping at all.

If the pause comes with other signs — a pale comb, lethargy, weight loss or odd droppings — it’s worth a word with a vet or an experienced keeper, as illness and parasites can also be to blame.

When do chickens stop laying?

A hen lays most prolifically in her first two years. After that, output declines by roughly 10–20% a year as she ages — though the eggs she does lay tend to get larger. Many hens keep laying intermittently into their fifth, sixth or seventh year, just less often.

There’s a hard biological limit underneath all this: a hen is hatched with a finite stock of tens of thousands of tiny undeveloped ova — every egg she will ever lay is, in a sense, already present at birth. She simply works through them more slowly as the years pass.

Feeding for eggs

Laying is metabolically expensive, and feed is where keepers most often go wrong. From point of lay (around 18 weeks), hens should move onto a proper layer feed or layer pellets — typically about 16% protein and fortified with calcium. Calcium is the big one: each shell takes a remarkable amount of it, which is why a separate dish of crushed oyster shell is standard, letting hens top up as their bodies demand.

The classic mistake is over-treating. Scratch grains, kitchen scraps and mealworms are fine in moderation, but if they crowd out the balanced layer feed, protein and calcium drop and so do the eggs — often the real reason behind a mysterious slowdown. Fresh water, always available, matters just as much; even a short shortage can interrupt laying.

Nest boxes: where the eggs actually appear

Give hens a tidy, private place to lay and they’ll mostly use it. The rule of thumb is one nest box for every three to four hens — they’ll happily queue for a favourite rather than spread out. Boxes should sit lower than the roosting bars (so birds don’t sleep and soil in them), in a dim, draught-free corner, lined with soft bedding like straw or wood shavings.

A ceramic or wooden “dummy egg” placed in a box is an old trick to show new layers where to go. Collect eggs daily: it keeps them clean, discourages egg-eating, and reduces the chance of a hen deciding to go broody on a growing pile.

The record-breakers

The official world record is almost unbelievable: a White Leghorn known only as No. 2988 laid 371 eggs in 364 days in a formal test at the University of Missouri that ended in August 1979 — more than one a day, sustained for a year. It’s why Guinness lists the Leghorn as the most prolific chicken, and arguably why white eggs dominate supermarket shelves.

The heritage record belongs to the Australorp, an Australian breed developed from Orpington stock for sheer laying ability. In a 1920s Australian laying trial, one hen managed 364 eggs in 365 days — and a team of six reportedly averaged over 300 each — all without any artificial lighting, which makes the feat even more striking. No backyard hen will match these, but they show what the species is capable of.

Common questions

Sources

• Guinness World Records — most prolific chicken: White Leghorn No. 2988, 371 eggs in 364 days (University of Missouri, 1979).
• Omlet / poultry breed guides — Leghorn, ISA Brown, Australorp and heritage breed laying averages; the Australorp 364-eggs-in-365-days trial.
• Backyard poultry references — point of lay age, moult and daylight effects, layer-feed and calcium needs, nest-box ratios, and egg-colour genetics.

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