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How fast do baby chicks grow?

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How fast do baby chicks grow?

Most people buy day old baby chicks for their potential.  Either your chicks will grow into an egg-laying machine, or they will get jacked to the core and offer some tasty meat as broiler chickens.  The only exception is if you're using chicks as live prey for snakes or raptors.  Chicks are superior to rodents, but can grow quickly, so you'll either need to use them all right away, or freeze some for a future feeding. 

But if you're not a snake owner, and truly want your baby chicks to grow, it's good for planning purposes to know just how fast these birds can develop.  And baby chicks will grow quick.  

1 Day Old Chicks

1 day old chicks

When buying chicks online, most people will not see the chicks the same day they are hatched.  That is because these chicks are shipped out the day they are hatched, and a few days will go by to account for the transit time.  When most people receive their chicks, they will be about 3 or 4 days old.

The chicks in the image above are 1 day old.  When they hatch, they are very fuzzy feathers.  These feathers are called down feathers, and will help keep these newborns warm.  As we learned in another article, keeping chicks warm is critical to ensuring they grow into healthy adults.

Day old chicks will stand at about 4" tall.  But many of them will still be sitting just like the 2 in the image above.


When you set up you brooder, you'll need to make sure your day old chicks have a heat source that can warm an area to about 95 degrees F.  Down feathers are nice, but they are not dense enough to protect a chick from external temps.  So it's important to have their heat source readily available as soon as you get them in the mail.

2 day old chicks

After a day of stretching, wondering, and exploring, these baby chicks have successfully survived to 2 days old!  Just like yesterday, they are still only covered in down feathers.  Many still keep their heads tucked, but a few will go so far as stretching their necks to get a better look at the surroundings.  The chicks who still tuck their heads are measured at about 4" tall.  But the tall chicks who are curious enough to stretch their necks are about 5" tall.  Which is pretty impressive considering they measured at about 4" the day before.


Day old chicks don't generally eat on their first day of life.  They may be ready to start eating the 2nd or 3rd day.  You'll want to have the correct food available,  and your feed mill store will have the proper mixture.  Because newborn chicks have a lot of growth to go through, they will need a lot of protein in their diets.  And the chick starter feed will have the proper amount.  

3 day old chicks

day old chick

At 3 days old, you can start to see how quickly chickens grow.  They are more curious, more mischievous, and weren't nearly as scared as prior days.  At 3 days old, you can see some chicks starting to develop their primary feathers on their wings.  Not all the chicks will develop this quickly, but you can anticipate that the remaining chicks will soon display these premature primary feathers.  

4 day old chicks

A 4 day old chicken doesn't look much different than a 3 day old.  You can start to see more primary feathers get developed.  But aside from that, their personality is still curious, and they're still predominantly covered in down feathers.  And they still stand at about 5" in height.

5 Day Old Chicks

There still isn't much noticeable difference between a 4 day old chick and 5 day old.  But if you had them in their brooder, you will notice that they are quicker, more nimble, and enjoy flapping their wings more.   At this stage in their life, they are familiar with their surroundings and brooder, and will fearfully explore and forage through the bedding that you provide for them.  

6 Day Old Chicks

At 6 days old, your chicks will be standing nearly 6" tall.  This is a 50% increase in height compared to the day they were born.  Which is pretty phenomenal growth rate.  And at this point, all if your chicks will be showing off the primary feathers  on the tips of their wings.  However, most of their body will still be covered in down feathers.

7 Day Old Chicks

Baby chicks experience significant growth after their first week of life.  They'll immediately start to display their primary feathers.  And their height will increase by about 50%.  By this time, your chicks may start to demonstrate their ability to jump and flap at the same time.  Depending on the height of your brooder, you may need to consider expanding the height.  Plastic kiddie pools are popular brooder set ups.  But a week old chick will likely be able to leap out of that pool.  So it'll be time to consider a new brooder set up after the chicks achieve their first week.


After the first week of development, chicks will still need their heat source.  But you can turn the heat down to about 90 degrees F.  If you're using a heat lamp, you can raise the bulb to reduce the heat.  As you can see, they are starting to grow some of their primary feathers, but they are still predominantly covered in down feathers.  

8 Day Old Chicks

If your brooder's walls aren't taller than 12" at this point, then your chicks are going to have an easy time jumping out of their brooder.  Wing flapping and stretching is a common exercise at this point, and these chicks love to perch.  So the  edge of your brooder will be a perfect target for these 8 day old chicks.

9 Day Old Chicks

At day 9, your baby chicks will stand tall at nearly 7" in height.   By this time,  your chicks are going to consume nearly double the amount of food they did a week before.  So you'll need to keep a chronic eye on their feeders, and make sure they are always loaded with starter food.  Also, they will love making a mess our of their water.  

10 Day old Chicks

Now those are some nice looking wings!  They're still predominantly covered in down feathers on their 10th day of life.  But at this point, you can really see the primary and even some secondary contour feathers taking shape.  This is how these baby chicks start to jump extraordinary heights.  Your may think you 2' tall brooder can contain these adventurous chicks.  Only until you come home and see them all over your garage or barn floor.

11 Day Old Chicks

These curious birds are still strong and flapping hard.  They love to eat, kick up bedding, explore and perch.  They will run together, and will try their hardest to escape their brooder.  If your brooder isn't large enough, you'll want to keep a constant eye on them.  Because they're curious minds will want to make a run for it.

12 Day Old Chicks

There isn't much difference between a 12 day old chick and an 11 day old chick.  At 12 days, they're standing nearly 8" tall when fully stretched out.  But if you look at the white novogen leghorns, you'll notice that their wings have lost most of their down feathers, and are nearly covered in primary and contour feathers.  This feather development on their wings helps them elevate when they jump, which is why you'll need to keep very high walls on their brooder, or keep a roof over top their brooder.  Because they will get out.  And at around this age, they will eat nearly double the amount of food than they were eating a week earlier.  


In a few days, you'll be able to reduce their heat by another 5 degrees.  The primary feathers, and extra body mass can help them sustain body heat at this point.  But are still dependent on external heat sources.

28 Day Old Chicks (4 weeks)

Once these baby chicks hit 4 weeks, they start to look like traditional chickens.  They've lost nearly all of their down feathers, and are almost fully feathered.  By this time, they will be too large for a brooder, and can be kept outside (assuming your night temps don't drop below 60 degrees F) in a coop.  You will still want to provide them with a heat source.  But at this point, the heat source only needs to sustain temps of about 80 degrees.  

4 week old chickens will not be ready to lay eggs.  That will start occurring between week 16-20.  


At this stage in their lives, you can offer more food into the chicks' diets.  Seeds, crickets, mealworms, and other sources of food are great options for your chickens.  Here is a video of them going hog-wild for some hearty superworms:

 35 day old Chicks (5 weeks)

If you made it to week 5, then you're on your way to yielding some high quality chickens.  At this stage, they should be fully feathered.  They may have a few follicles of down feathers remaining, but they'll disappear in a few days.  

Because they are fully feathered, you can safely reduce your heated area by another 5 degrees F.  75 degrees is a great temp for them at this stage.  However, don't be surprised if you see them traveling far beyond the heat.  Feathers are excellent forms on insulators, and do a great job keeping your chicks warm.  


At this point, you'll continue using the same starter food you were using a week ago.  Somewhere between week 6-8 is when you'll need to upgrade to a newer feed with less protein.  Your grain supplier will know which feed is best for your chicks.  

But don't be afraid to offer them some treats.  Chickens love treats and insects, fruit and vegetables are a preferred source of food.  And for whatever reason, they'll go bonkers for pumpkin and squash.

1 comment

  • Thanks so much for the information, kudos 👍

    Anne Masakhwe on

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