Learning how to incubate chicken eggs is one of the most rewarding ways to grow your flock, and with a little preparation it is well within reach for beginners. This guide walks you through sourcing fertile eggs, setting up and running an incubator, turning and candling your eggs, the 21-day timeline, and caring for your newly hatched chicks.
Short answer: Chicken eggs hatch in about 21 days when incubated at a steady 37.5Β°C (99.5Β°F) with controlled humidity, gentle ventilation, and regular turning until the final three days, when you stop turning and raise the humidity for "lockdown".
Before you begin, remember that you are likely to hatch as many cockerels as hens, so have a plan for the boys. Keeping several cockerels long term is challenging, rescues are already full, and rehoming responsibly takes effort. If you are happy to plan for that and want to hatch your favourite breed affordably, incubating your own eggs could be perfect for you. (If you are still weighing it up, our guide to the pros and cons of hatching chicks is a great place to start.)
Broody Hen or Incubator: Which Should Beginners Choose?
Many pure-breed hens go broody naturally as the days lengthen and the weather warms. A broody hen is the cheapest way to incubate eggs, but it relies on having the right bird at the right time. Sometimes a hen will get halfway through sitting and lose interest, which can be heartbreaking. If you have a reliably broody hen, you can make the most of her: see our tips on how to make a Nestera coop perfect for a broody hen.
Incubators tend to be more reliable and predictable, and you generally get what you pay for. Models that turn the eggs automatically are well worth the extra cost, as consistent turning is one of the biggest factors in a successful hatch.
How to Source Fertile Hatching Eggs
If you do not already keep a breeding group of several hens and a cockerel, you will need to source fertile eggs elsewhere. Many breeders sell hatching eggs from their breeding groups online, but try to collect them in person if you can. That way you can see the parent stock and check the conditions they are kept in.
Collecting in person also avoids the post or a courier, as the jostling and temperature swings of transport can reduce hatch rates in fertile eggs.
How to Test Whether an Egg Is Fertile
You can check whether an egg is fertile without incubating it. Simply crack one open onto a clean plate and look at the yolk. You will see a small white spot called the blastodisc. If it is a solid spot, the egg is infertile; if the spot looks like a ring with a dot in the centre, it is fertile and is then known as a blastoderm. (You will only test a sacrificial egg this way; the rest you assess later by candling.)
Storing and Selecting Perfect Eggs
If you are collecting eggs from your own flock, gather them several times a day and clean the nest box daily to keep eggs as clean as possible and minimise pathogens. Store them in a cool, dark place, pointy end down. Discard any cracked eggs, and if you are holding them for several days before setting, turn them regularly so the yolk does not settle.
Why You Should Set at Least a Dozen Eggs
Always try to incubate at least a dozen eggs. If you only set six, you could end up with a single chick. A lone chick can become stressed, and finding a similar-aged friend at short notice is often very difficult. Setting a full dozen gives you the best odds of hatching a small, sociable group.
Here are some quick tips from our hen guru.
Setting Up Your Incubator: Cleaning and Placement
Before you start, wash your incubator with hot water and mild detergent, rinse well, and disinfect with a specialist product. Dry it thoroughly and run it empty for at least 48 hours before filling, so you can confirm it holds a stable temperature.
Site the incubator in a quiet room, away from boisterous pets and inquisitive children, and well clear of heat sources, direct sunlight, or draughts that could cause temperature swings. Aim for a steady internal temperature of 37.5Β°C (99.5Β°F), and always double-check the display against a separate sterilised thermometer. Make sure the incubator's air vents are not blocked, as developing embryos need a gentle, constant supply of fresh air.
Getting Incubation Humidity Right
Humidity matters as much as temperature. In a damp climate such as the UK, you may need to add less water than the instructions suggest, because there is already plenty of moisture in the air. This is a genuinely contentious topic and experienced keepers often do it differently.
As a general guide, many keepers aim for around 45β50% relative humidity for the first 18 days. Too much humidity can cause the egg to retain too much water, which can drown the chick as it hatches, and it can also encourage bacterial build-up. Too little, and the air cell may grow too large. Watching your candling results (below) will tell you whether your humidity is roughly on track.
Ready, Steady, Go: Setting Your Eggs
When everything is finally ready, wash and dry your hands thoroughly and place the eggs in the incubator. The temperature will drop briefly while you do this, but don't panic, it will soon warm back up. Mark day one on the calendar so you can count down to hatch day.
Make a small pencil mark on the top of each egg so you can confirm the turning mechanism is working (or, if turning by hand, that you have turned them all). Incubation periods vary by species: quail take around 18 days, bantam chickens 19 days, large-fowl chickens the classic 21 days, while ducks, turkeys, and geese take about 28 days, and Muscovy ducks can take over 35 days.
Candling Eggs to Check Development
Candling is how you check that your eggs are developing, and it is one of the most satisfying parts of incubation. In a dark room, hold a bright, focused light (a dedicated egg candler or a small torch) against the broad end of the egg. By around day 7 to 10 you should start to see a network of blood vessels and a small dark embryo, often with visible movement.
Eggs that stay clear with no veins by day 10, or that show a dark ring, are usually not developing and can be removed so they do not spoil and contaminate the rest. Candling again before lockdown lets you see the growing air cell and confirm your humidity has been about right.
Lockdown and the Final Countdown to Hatch
Three days before your chicks are due (around day 18 for chickens), it is time for "lockdown". Switch off any auto-turn feature, stop turning the eggs, and increase the humidity to roughly 65β75%. You can raise humidity by adding water to the incubator's reservoir or trays, rather than spraying the eggs directly.
Try not to open the incubator again until all the eggs have hatched, or until 24 hours have passed since the first chick hatched. Opening it releases the humid air the chicks need to break free of the shell. Don't worry that they will go hungry: chicks absorb the remainder of the yolk into their tummies just before hatching, so they don't need to eat or drink for the first day or so. Hatching can be slow, so resist the urge to help.
Caring for Newly Hatched Chicks: Brooder Basics
Once chicks are fluffy and dry, move them to a clean, draught-free brooder. The key things they need are warmth, food, water, and space:
- Warmth: Provide a heat source (a heat plate or lamp) so one area sits around 35Β°C (95Β°F) for the first week, reducing by roughly 3Β°C each week. Always leave a cooler zone so chicks can move away from the heat if they get too warm.
- Food and water: Offer a good-quality chick crumb and shallow, clean water (with pebbles or marbles in the dish to prevent drowning).
- Bedding: Use a non-slip, absorbent bedding and keep it clean and dry.
- Space and safety: Keep the brooder secure from other pets, and check chicks frequently.
As your chicks feather up and grow, they will eventually be ready to move outdoors to a coop. A clean, easy-to-maintain home makes that transition far simpler, which is exactly where a hygienic, smooth-surfaced coop comes into its own.
Frequently Asked Questions About Incubating Chicken Eggs
How long does it take to incubate chicken eggs?
Most chicken eggs hatch after about 21 days of incubation. Bantams can hatch a little earlier (around 19 days), and a day either side of 21 is completely normal for large-fowl breeds.
What temperature and humidity do chicken eggs need?
Aim for a steady 37.5Β°C (99.5Β°F) throughout incubation. Many keepers target around 45β50% humidity for the first 18 days, then raise it to roughly 65β75% during the final three days (lockdown) to help the chicks hatch.
When should I candle my eggs?
Candle around day 7 to 10 to check for blood vessels and a developing embryo, then again before lockdown. Remove any eggs that are clear with no veins or show a dark ring, as these are usually not developing.
My chicks have hatched, what do they need first?
A warm, dry, draught-free brooder with a heat source, chick crumb, and clean shallow water. Newly hatched chicks can go without food and water for the first day because they absorb the remaining yolk just before hatching. For any signs of illness, always consult your vet or a qualified poultry specialist rather than treating chicks yourself.
Ready to Welcome Your New Flock?
Hatching your own chicks is hugely rewarding, and giving them a clean, secure home sets them up for a healthy life. Nestera's recycled-plastic chicken coops are smooth, easy to clean, and free of the cracks where red mites love to hide, making them a low-maintenance, hygienic choice for your growing flock. If you are wondering about timing, you might also enjoy our guide on whether chicks can hatch in winter. Happy hatching!
