Enter the date your eggs were set and the species — get lockdown date, expected hatch window, candling schedule, and a full day-by-day milestone table so you never miss a critical step.
Incubation timing is species-specific and missing lockdown by even a day can mean chicks dying in the shell. This calculator accounts for each species' exact incubation period and gives you a complete schedule from set date to hatch.
Getting the temperature and humidity right is the difference between a healthy hatch and a failed one. Most species incubate at 99.5°F (37.5°C) in a forced-air incubator, or 101–102°F in a still-air unit. Humidity should sit between 45–55% for most of incubation, then jump to 65–75% at lockdown.
Hatch rates of 70–85% are typical for shipped eggs; 85–95% for eggs from your own flock. Shipped eggs are stressed in transit and should rest large-end-up at room temperature for 12–24 hours before setting.
Chicken eggs go into lockdown on day 18 — three days before the expected day 21 hatch. On day 18, stop turning, remove the egg turner if applicable, increase humidity to 65–70%, and do not open the incubator until the hatch is complete.
Candle in a dark room by pressing a bright LED flashlight firmly against the large end of the egg. At day 7, a fertile egg shows a dark embryo mass with a spider-web of blood vessels. An infertile egg looks clear. A dead embryo (quitter) shows a blood ring around a dark mass with no visible movement.
Most eggs incubate at 45–55% relative humidity for the majority of incubation. At lockdown, raise humidity to 65–75%. Higher humidity at hatch keeps the membrane soft so chicks can break out. Too low and the membrane dries and shrink-wraps the chick.
Coturnix (Japanese) quail eggs hatch in 17 days. Bobwhite quail take 23 days. Set lockdown on day 14 for coturnix. Quail eggs are tiny — candle them carefully with a bright flashlight, as they can be harder to read than chicken eggs.
Some variation is normal. Eggs set on different days, slight temperature variation, and breed differences mean hatch can range from day 20–23. Keep the incubator closed and wait until day 23 before concluding an egg has failed. After the hatch is done (24–48 hours after the first chick), candle any remaining eggs to check for late quitters before discarding.