Chicken Egg Incubation Calculator

21 days from setting, on average. Chicks can arrive a day or two early or late, so treat day 21 as the center of a hatch window (roughly day 20 to 22), not an appointment.

Day 18. Stop turning, remove the turner, raise humidity to 65-70%, and do not open the incubator again until the hatch is done. Lockdown for other species is generally 3 days before the expected hatch date; this calculator sets it automatically per species.

First candling around day 7 to 10 to remove clear (infertile) eggs, and a second check around day 14, with an optional final look at day 18 before lockdown. For other species, the calculator scales candling to roughly one-third and two-thirds through incubation.

In a forced-air incubator: 99.5F (37.5C) and 50-55% relative humidity for days 1 to 18, then 65-70% humidity during lockdown (days 19 to 21). Still-air incubators run a bit higher, around 101-102F measured at the top of the eggs.

It is possible but fiddly: ducks need 28 days versus 21 for chickens, and duck eggs prefer higher humidity. The common workaround is to set the duck eggs a week before the chicken eggs so lockdowns and hatches line up, and run humidity around 55%.

Yes. Each opening drops humidity sharply, and low humidity during hatch causes chicks to get "shrink-wrapped" in the membrane and stuck. Fill water through an external port if your incubator has one, and let the chicks dry in the incubator before moving them to the brooder.