How to use the egg incubation calendar calculator
- Add a batch for each group of eggs: a name, the species and the day you set the eggs in the incubator.
- If a species is not in the list, choose "my own days" and enter the number of days in the box below the list.
- Open the advanced options to change the candling days and the number of lockdown days before the hatch.
- Read the calendar: the dates for candling, lockdown and the expected hatch for every batch, with the day of the week.
Formula
hatch date = day set + incubation days (the day set is day 0)
candling dates = day set + chosen candling days
lockdown date = hatch date - lockdown days
The incubation days are example values for each species. The dates are plain calendar arithmetic, with leap years handled.
A chicken batch and a duck batch
Chicken eggs set on Sunday, November 1, 2026 with 21 days of incubation hatch on Sunday, November 22. Candling on days 7 and 14 falls on Sunday, November 8 and Sunday, November 15, and lockdown 3 days before the hatch is Thursday, November 19.
Duck eggs set on November 8 with 28 days hatch on Sunday, December 6, with candling on November 15 and 22 and lockdown on Thursday, December 3. Quail eggs set on February 20, 2028 with 18 days hatch on Thursday, March 9, 2028, since 2028 is a leap year.
About the numbers
The days used here are 21 for chicken, 28 for duck and turkey, 35 for Muscovy duck, 30 for goose, 28 for guinea fowl and 18 for Japanese quail. Goose and quail vary between sources, and every number shifts with breed, temperature, humidity and the age of the eggs. Use the figure from your incubator guide or your breeder, and change it with the "my own days" option.
Candling means checking the eggs with a light to see development. Lockdown is when turning stops and humidity is usually raised for the hatch. The days for both are settings you choose, not rules. Eggs often hatch a day early or late, so keep the incubator running a little past the expected date.
Planning for the hatch
Staggering batches spreads the work but means that the incubator is opened during another batch's lockdown, so many keepers set eggs in groups. The calendar lists every batch so you can see overlaps. Plan the space the birds will need next with the chicken coop size calculator, and the running costs with the backyard chicken egg cost calculator. For dates in general, use the date calculator.
Assumptions and limits
- The incubation days are example values. Your incubator guide or breeder has the right figure for your eggs.
- The day set counts as day 0, so a 21-day batch set on day 0 hatches on day 21.
- The candling days and lockdown days are settings you choose and must fall before the hatch date.
- Between 1 and 12 batches are accepted.
Frequently asked questions
Does it count the day I set the eggs?
The day you set them is day 0, and the hatch is the set day plus the incubation days. Some keepers count the set day as day 1; if you do, subtract one day from the dates shown.
When should I stop turning the eggs?
Many guides say to stop a few days before the hatch, which is the lockdown date. The right number of days depends on the species and your incubator, so follow its guide.
Can I add a species that is not listed?
Yes. Choose "my own days" and enter the number of days. It applies to every batch that uses that choice.
What if an egg hatches early or late?
It happens. Cooler temperatures slow development and warmer ones speed it up. The dates here are a plan for a well-run incubator, so allow a day or two on either side.