Molting Calculator
A hen hatched on 1 March 2025 has her first adult molt in about September 2026, lasting 8 to 16 weeks. This molting calculator works out the molt window from the hatch date — first molt at about 18 months, then every autumn — and estimates when laying resumes. Laying drops or stops during the molt while feathers regrow.
Molting Calculator
Planning estimate. Figures vary by breed, strain, climate and management — see the sources cited on this page.
Key facts
- First adult molt at about 18 months old (about 20 months for heavy breeds), then every autumn after that.
- Molt duration: 8–16 weeks. Fast moulters finish in about 8 weeks; slow moulters take up to 16.
- Laying stops or drops sharply during the molt, because the hen puts protein and energy into feathers instead of eggs.
- Shortening daylight triggers the molt. That is why it falls in autumn, and why extra coop light can delay it — see the chicken coop lighting calculator.
- Feathers are almost all protein. Offer a higher-protein feed during the molt and avoid handling moulting birds: new pin feathers are tender and bleed if broken.
When will my chickens molt?
At about 18 months old for most layers, then every autumn. A hen hatched on 1 March 2025 has her first adult molt in about September 2026. Heavy breeds such as Orpingtons, Brahmas and Cochins tend to start a little later, at about 20 months. Enter the hatch date above and the calculator gives the month, the 8 to 16 week window, and the next annual molt.
How long does molting last in chickens?
8 to 16 weeks. Fast moulters drop feathers quickly, look almost bare for a while and finish in about 8 weeks; slow moulters lose feathers gradually and can take up to 16 weeks. Laying usually stops or drops sharply for the whole molt and resumes roughly 2 to 4 weeks after the new feathers are in. A hen that is still laying well in late autumn is often a slow moulter, not a hen that skipped the molt.
What to do during the molt
Feed a higher-protein ration while feathers regrow, keep fresh water available, and handle moulting birds as little as possible — new pin feathers are tender and bleed if broken. Do not add light to force laying through the molt; the rest is part of the cycle. Expect fewer eggs for two to four months and plan the flock around it: a mixed-age flock keeps some eggs coming while older hens moult.
What this calculator does not do
It cannot predict the exact week a hen starts moulting — daylight, feed, stress and individual variation all shift it by weeks. It also does not cover juvenile moults: chicks replace their down several times in the first weeks, which is normal growth, not the adult molt. If a hen loses feathers outside autumn, look for parasites, bullying or feather pecking before assuming a molt.
Frequently asked questions
When will my chickens molt?
Hens have their first adult molt at about 18 months old, then every autumn. A hen hatched on 1 March 2025 moults first in about September 2026. Enter the hatch date in the calculator above for the month, the 8 to 16 week window, and the next annual molt.
What is a chicken molting calculator?
It works out when a hen will moult from her hatch date. The first adult molt comes at about 18 months old, then every autumn, lasting 8 to 16 weeks. It also estimates when laying resumes, roughly 2 to 4 weeks after the new feathers grow in.
When do hens molt and stop laying?
Hens moult in autumn, when shortening daylight triggers feather replacement, and laying drops sharply or stops for the molt. The molt lasts 8 to 16 weeks, and eggs usually return 2 to 4 weeks after the feathers regrow.
How long does molting last in chickens?
8 to 16 weeks. Fast moulters finish in about 8 weeks; slow moulters take up to 16 weeks. Laying stops or drops for the whole molt and resumes roughly 2 to 4 weeks after the new feathers are in.
Do chickens lay eggs while molting?
Usually not, or very few. A moulting hen puts protein and energy into growing feathers instead of eggs, so laying drops sharply or stops. Eggs return once the new feathers are in, typically 2 to 4 weeks after the molt ends.
The Chick Brooder Temperature by Week guide covers the same part of keeping chickens in more detail. Two related calculators worth checking next are the Chick Brooder Size Calculator and Brooder Temperature Calculator.