Egg Incubation & Hatch Date Calculator
How day counting works
This calculator treats the set date as day 0. Hatch calendar date equals set date plus the species incubation length. Lockdown calendar date equals set date plus (lockdown day number − 1), so a chicken lockdown on day 18 after a March 1 set lands on March 18, with hatch on March 22 (day 21). State that convention on every printout — charts that call set day “day 1” will look one day early.
The chicken timeline
Chickens incubate 21 days. Turn eggs three to five times daily until lockdown, 3 days before hatch. Raise humidity into the 65–70% RH band and stop turning so chicks can pip and zip without rolling. Forced-air machines run about 99.5 °F; still-air units run warmer at the top of the eggs (101.5 °F) because air stratifies.
Early candling (around day 7) removes clear eggs if you are comfortable identifying veins. A second look before lockdown catches early deaths. Resist opening the incubator during hatch — humidity crashes and membranes can shrink-wrap chicks.
Temperature and humidity by species
Species lengths in our data: chicken 21, duck 28, turkey 28, Coturnix quail 17.5 (17–18 midpoint), goose 30 (typical; 28–32 occurs in the field). Humidity bands shown in the schedule are the chicken planning standard (45–50% before lockdown, then 65–70%). Waterfowl often want higher humidity — follow your hatchery card when it conflicts with the chicken default. Muscovy ducks and other long-cycle species are outside this data file.
Lockdown explained
Lockdown is the quiet period when embryos move into hatching position. Stop turning, top up water channels for the higher RH band, and leave the machine closed unless temperature is clearly wrong. Helping a chick out is a last resort after more than 24 hours stuck at pip with a dry membrane — most assisted hatches need extra care afterward.
Candling without wrecking the hatch
Candle in a dark room with a bright, cool LED. Look for a spiderweb of vessels early, then a growing dark mass with a distinct air cell later. Remove only eggs you are sure are clear or blood-ring early deaths — guessing wrong throws away a late bloomer. Sanitize hands and minimize how long trays sit outside the machine. If your incubator loses heat quickly, candle fewer eggs per session.
Quail eggs are harder to read through spotted shells; trust weight loss and a final candle more than aggressive culling. Goose and duck eggs are large — give them room so turning fingers or rails do not crack shells. Always mark the set date on the incubator lid so lockdown is not a surprise.
Troubleshooting low hatch rates
- Temperature swings. A degree high for days cooks embryos; chronic lows delay hatch and increase malpositions. Verify with a second thermometer.
- Humidity extremes. Too dry yields sticky chicks; too wet leaves drowned or unabsorbed yolks. Weigh a sample of eggs if your incubator supports loss-tracking, and adjust water surface area rather than guessing.
- Old or shipped eggs. Fertility and hatchability fall after about a week of storage; shipped eggs need rest pointy-end down before setting. Expect lower hatch from mail-order eggs than from a fertile nest next door.
- Turning gaps. Missing turns in the first two weeks sticks membranes and raises malposition risk. Automatic turners fail quietly — check that trays actually move.
Frequently asked questions
How long do chicken eggs take to hatch?
21 days from set (day 0) to hatch date.
What day is lockdown for chicken eggs?
Day 18 — 3 days before hatch.
How long do duck eggs take?
Most common ducks about 28 days in this data set.
Why 99.5 °F?
That is the standard forced-air setpoint. Still-air incubators read higher at egg height because heat layers.
Can I open the incubator during hatch?
Avoid it. Opening dumps humidity when chicks need a moist environment to hatch cleanly.
What humidity for hatching?
Chicken planning band at lockdown: 65–70% RH.
Incubator gear we'd buy
| Product | Capacity | Auto-turn | Best for |
|---|---|---|---|
| Nurture Right 360 | 12–22 eggs | Yes | A first hatch, or a family-sized batch |
| Brinsea Mini II Advance | 7 eggs | Yes | Small, deliberate hatches of a prized breed |
| Digital thermo-hygrometer | — | — | Every incubator, whatever you paid for it |
| Govee WiFi hygrometer | — | — | Hatching while away from the machine all day |
Nurture Right 360
Best for most
Brinsea Mini II Advance
Premium pick
Digital thermo-hygrometer
Must-have add-on