Knowing your hatch and lockdown dates keeps an incubation on track. Enter the day you set the eggs and the species, and this calculator returns the lockdown date, the expected hatch date, and the window during which you should keep turning the eggs.
How it works
Each species has a standard incubation period from the day of setting (day zero):
chicken 21 days duck 28 days
quail 17 days goose 30 days
turkey 28 days pheasant 24 days
guinea 28 days peafowl 28 days
hatch date = set date + incubation period
lockdown date = set date + (incubation period − 3)Turn the eggs from day one until lockdown, then stop. The three-day lockdown window before hatch is when you raise humidity and leave the incubator closed.
Incubation temperature and humidity guide
The most critical variables are temperature and humidity. Small deviations that persist for several hours can set back the hatch by a day or kill developing embryos.
| Stage | Temperature (forced-air) | Humidity (relative) |
|---|---|---|
| Days 1 to lockdown | 37.5 °C (99.5 °F) | 50–55% |
| Lockdown to hatch | 37.5 °C (99.5 °F) | 65–70% |
Still-air incubators run slightly warmer — typically 38.3–38.9 °C (101–102 °F) at the top of the egg — because the temperature gradient means the egg surface is cooler than the air reading. If your incubator lacks a fan, check the manufacturer’s recommended temperature for still-air operation rather than applying the forced-air figure.
Humidity requirements vary by climate. In very dry environments you may need to add water more frequently; in humid climates you might not need to add water at all during early incubation. Candling at lockdown is the most reliable check: a good air cell size (roughly one-third of the egg volume by day 18 for chickens) confirms humidity was about right throughout.
Egg turning: why it matters and when to stop
Turning prevents the embryo from sticking to the shell membrane, which is lethal in the early stages. Turn eggs at least three times daily, preferably five or more, and always an odd number of times so the egg rests on alternating sides overnight. Automatic egg turners greatly improve hatch rates in larger incubators.
Stop turning at lockdown — three days before the expected hatch date — and do not open the incubator again until chicks have dried (usually 24 hours after the last chick hatches). Opening during hatch lets humidity escape precisely when it is most needed to soften the membrane and let chicks pip through the shell.
Candling schedule
Candling with a bright LED torch in a dark room lets you check development without opening the incubator:
- Day 7 — look for a network of blood vessels radiating from a dark centre. Clear eggs with no development can be removed, but give borderline ones another few days.
- Day 14 — the embryo should occupy most of the egg. The air cell at the blunt end should be clearly visible.
- Day 18 (lockdown) — the air cell should be large and the egg mostly dark. Remove any remaining clear or blood-ring eggs before lockdown.
What to expect at hatch
Chickens typically begin to pip (make the first hole in the shell) on day 21, though some may start a few hours earlier or later. Once a chick has begun pipping, it can take 12–24 hours to fully emerge — this is normal. Do not assist unless a chick appears exhausted and has not made progress in over 24 hours after pipping. Hatching chicks need the exercise of breaking out for their own development.
Allow two to three extra days before discarding eggs, since temperature swings and egg size shift timing. The schedule here assumes incubation begins the moment eggs enter the warm incubator, not when they were laid.