Egg Incubation Calculator

Incubation periods at a glance

Incubation periods per Mississippi State University Extension. Goose varies 28–35 days by breed; Muscovy ducks run ~35 rather than 28.

How this calculation works

Every date this calculator produces is counted from your set date — the day eggs go into a running, pre-warmed incubator, which counts as day 0. Chicken eggs hatch on day 21, ducks and turkeys on day 28, Coturnix quail around day 17, and geese around day 33 (Mississippi State University Extension figures). Real hatches spread a day either side: a slightly warm incubator speeds development, a cool one slows it.

Candling happens on day 7 and day 14 (with an extra check for the longer species). At day 7 a fertile egg shows a spiderweb of veins around a dark dot; an infertile egg glows clear. Pull the clears and any eggs showing a blood ring — leaving them risks a rotten egg bursting and contaminating the hatch. Day 14 confirms everyone left is still growing.

Lockdown is always three days before hatch — day 18 for chickens. Three things change at once: the turner stops (chicks are positioning for hatch and turning now disorients them), humidity goes up to 65–70% (so shell membranes stay soft enough to break through), and the lid stays closed until hatching finishes. Every peek during lockdown dumps the humidity you're trying to hold.

A worked example

Set chicken eggs on March 1st. Candle on March 8th (day 7) and pull the clears; candle again on March 15th (day 14). On March 19th (day 18), take the eggs off the turner and raise the humidity — that's lockdown. Expect pipping around March 21st and chicks out on March 22nd, day 21. If nothing has hatched by day 23, candle before giving up — late hatches happen, especially with shipped eggs or a cool incubator.

One planning tip: count backward, not forward. If you want chicks in time to have layers by fall, or ducks before a farm swap, put your target hatch date into the calendar and set eggs 21 (or 28, or 33) days earlier. And set on a weekend — lockdown then also lands on a weekend, when you can actually watch the hatch.

Frequently asked questions

How long do chicken eggs take to hatch?

Chicken eggs hatch 21 days after they are set in the incubator (Mississippi State University Extension). Ducks and turkeys take 28 days, Coturnix quail about 17, and geese roughly 33 depending on breed. A day or two either side is normal — slightly warm incubators hatch early, cool ones late.

What is lockdown and when does it start?

Lockdown is the final three days before hatch: you stop turning the eggs, raise humidity to about 65–70%, and keep the incubator closed. For chicken eggs that means day 18 of 21. Opening the incubator during lockdown drops the humidity and can shrink-wrap chicks mid-hatch.

When should I candle my eggs?

Candle at day 7, when veins and a moving embryo confirm fertility, and again at day 14 to remove any eggs that stopped developing. Eggs that are clear at day 7 or show a blood ring are not developing and should be pulled so they don’t rot in the incubator.

What temperature and humidity should the incubator be?

For chicken eggs in a forced-air incubator: 99.5°F, with 45–55% relative humidity for days 1–17, raised to 65–70% for lockdown and hatch. Still-air incubators run about 101–102°F measured at the top of the eggs. Waterfowl eggs like slightly higher humidity throughout.

Do I turn the eggs myself?

Eggs need turning at least 3 times a day (odd number, so they never sit the same way two nights running) until lockdown. Most incubators have an automatic turner — if yours does, your only turning job is switching it off at lockdown.

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