How to Incubate Chicken Eggs: A 21-Day Step-by-Step Guide
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Chicken eggs hatch in about 21 days. Keep a forced-air incubator at 99.5°F (37.5°C), hold humidity around 40 to 50%, turn the eggs several times a day, then stop turning and raise humidity to 65 to 70% for the final three days.
Hatching your own chicks is one of the most rewarding projects on a small farm or homestead. It is also very forgiving once you understand the few numbers that matter: temperature, humidity, turning and timing.
This guide walks through the full 21 days, from choosing fertile eggs to moving fluffy chicks into a brooder, with the checks that experienced keepers use to get high hatch rates.
By NovaAgri Team · Updated November 2026 · Based on poultry extension guidance and hatching experience
Key takeaways
- Incubation takes about 21 days for chicken eggs
- Forced-air incubators: 99.5°F (37.5°C); still-air: about 100.5 to 101.5°F measured at the top of the eggs
- Humidity 40 to 50% on days 1 to 17, then 65 to 70% for lockdown
- Turn eggs at least 3 times a day until day 18, then stop
- Candle on day 7 and day 14 to remove eggs that are not developing
What you will need
- An incubator with a reliable thermostat (forced-air is easiest)
- A separate thermometer and hygrometer to double-check readings
- Fertile hatching eggs, ideally less than 7 days old
- Clean water for the humidity tray
- A bright LED flashlight or egg candler
- A brooder, heat source, chick feed and waterer for after the hatch
Step-by-step: incubating chicken eggs
Set up and test the incubator
Place the incubator in a room with a steady temperature, away from windows, heaters and drafts. Run it for at least 24 hours before adding eggs, and check the reading with your own thermometer and hygrometer so you know it holds steady.
Choose and store fertile eggs
Pick clean, normal-shaped eggs without cracks. Do not wash them, because washing removes the protective bloom. If you need to store them before setting, keep them pointed end down at about 55 to 65°F and set them within 7 days for best results.
Set the eggs (day 1)
Let eggs warm to room temperature for a few hours to avoid condensation, then place them in the incubator. If you are turning by hand, mark one side of each egg with an X and the other with an O in pencil so you can track turns.
Hold temperature and humidity (days 1 to 17)
Keep a forced-air incubator at 99.5°F (37.5°C). Keep humidity around 40 to 50%, topping up the water channel as needed. Small swings are normal, but avoid opening the lid more than necessary.
Turn the eggs
Turn eggs at least three times a day, ideally an odd number of times so they do not rest on the same side every night. An automatic turner makes this effortless. Turning stops the embryo from sticking to the shell membrane.
Candle on day 7 and day 14
In a dark room, shine a bright light through each egg. On day 7 you should see a network of blood vessels and a dark spot; by day 14 most of the egg will look dark. Remove clear eggs and any with a blood ring, which indicates an early loss, to protect the rest of the hatch.
Lockdown (day 18)
Stop turning, remove the automatic turner if you use one and lay eggs on their sides. Raise humidity to about 65 to 70%. From now until the hatch, keep the lid closed: opening it drops humidity and can shrink-wrap chicks in their membranes.
Hatch day (day 21)
Chicks first pip a small hole, then may rest for many hours before zipping around the shell. This is normal. Resist the urge to help unless a chick has been stuck for a long time, and leave hatched chicks in the incubator until they are dry and fluffy, up to 24 hours.
Move chicks to the brooder
Transfer dry chicks to a brooder at about 95°F for the first week, lowering the temperature by about 5°F each week. Provide chick starter feed and fresh water with marbles or pebbles in the tray so chicks cannot drown.
- Watch chick behavior: huddled under the heat means too cold; spread far away means too hot
- Dip each beak in water to teach drinking
- Keep bedding clean and dry
Recommended gear
Pro tip: Most hatch problems come from humidity, not temperature. Weigh or candle your eggs to watch the air cell grow; if it stays small, lower humidity slightly, and if it grows too large, raise it.
Frequently asked questions
How long does it take for chicken eggs to hatch?
About 21 days. Eggs can hatch a day early or late depending on temperature and breed.
What temperature should an egg incubator be?
For forced-air incubators, 99.5°F (37.5°C). For still-air incubators, about 100.5 to 101.5°F measured at the top of the eggs.
What humidity is needed to hatch chicken eggs?
Around 40 to 50% for days 1 to 17, then about 65 to 70% from day 18 until hatching.
When should I stop turning eggs?
Stop turning on day 18, three days before the expected hatch, so chicks can position themselves to pip.
Can I open the incubator during lockdown?
Avoid it. Opening the incubator during lockdown lowers humidity quickly and can cause chicks to get stuck in their membranes.
The bottom line
Hatching chicks comes down to consistency: a stable 99.5°F, the right humidity for each stage, regular turning until day 18 and patience on hatch day. Start with a reliable forced-air incubator with an automatic turner, and your first hatch has an excellent chance of success.