How Big Are Baby Guppies?

As most fish lovers know, guppies are notorious breeders! I cannot count the number of times I’ve woken up and noticed tons of tiny guppies swimming around the tank. These little guys are so small that they are pretty hard to see – but how small are they really?

Baby guppies average 0.25 inches when they are born. They are fully formed at birth and grow to full size in around six months. Due to their size at birth, they are often vulnerable to being eaten by other fish or even their parents, so separating them from the main tank is necessary.

Because baby guppies are tiny at birth, they are tough to care for as they are so vulnerable. If you want to learn what to expect when your female guppy gives birth and how to protect these tiny fry, then take the time to read through this in-depth article on everything you need to know about baby guppies!

How Big Are Baby Guppies?

Baby guppies, or fry, are around 0.25 inches when born. Although they are tiny in comparison to adult guppies, they are fully formed at birth. Since guppies don’t lay eggs, their babies are born live miniature adults.

Guppy babies reach their full size six months after birth. Adult males are around 0.6 to 1.4 long, and females are between 1.2 to 2.4 long.

Although guppies only reach full size after six months, don’t think that these little fish won’t breed sooner! Guppies can start to reproduce after only two months after birth. It’s a great idea to keep this in mind if you want to prevent more babies from arriving!

Keeping Your Tiny Baby Guppies Safe

Due to their size, these little guys are very vulnerable at birth. It is highly common for the adult guppies, even their parents, to eat them – creepy, I know! It is, therefore, vital for you to protect your baby guppies if you want them to reach maturity.

You can protect your baby guppies by either moving them to a different tank or adding some greenery to your main tank!

Protecting Baby Guppies: Moving The Pregnant Female

The first way to protect your baby guppies is to move the pregnant female to a separate tank until she gives birth. I would suggest moving her before giving birth because trying to catch all your tiny guppies in your tank will prove an impossible task!

Once your female guppy has given birth, remove her and place her back into a recuperation tank, separate from the other adults, for a few hours to a day. The idea behind the recuperation tank is that she can have some time to recover and gain back her energy which is important for her health.

Once your baby guppies reach the minimum size of an inch long, then they are safe to be moved back to your main tank. However, it’s essential to look at the size of the fish in your tank because if you have very large fish, then maybe let your guppies grow a bit bigger before transferring them.

Guppies swimming near surface bubbles

Protecting Baby Guppies: Adding Live Plants

Another excellent way to protect your baby guppies is to add a variety of live plants into your tank!

Thick foliage provides a place for your baby guppies to hide and protect themselves from their parents as well as other larger fish. This is the more natural way to protect them as baby guppies in the wild hide in their natural habitat for protection.

Below you can find a list of some great plants for protecting your guppy babies:

  • Java Moss
  • Java Fern
  • Amazon Sword
  • Hornwort

Although this method is the more natural of the two, I would suggest separating your babies at least in the beginning because you might lose some babies if you only use this method.

A great idea is to separate your babies until they are around 1 inch in size, then place them back into your main tank with the addition of some live plants for protection. This makes sure that if they still need to seek shelter from a large fish, they then have the option.

How Many Baby Guppies Are Born At A Time?

The average number of guppy babies born at one time ranges from 20 to around 50 in one batch. If your female is healthy, she can reproduce every 30 days. That is a crazy number of babies if you’re not keeping an eye out!

Make sure to keep a lookout for a pregnant female so that your tank isn’t overloaded with babies.

Baby Guppies: What Does A Pregnant Female Look Like

There are a multitude of ways to tell if your guppy female is pregnant or not. I would suggest looking out for two things that I find the most obvious.

Firstly, the best indication is to look at something called the gravid spot on a female guppy. This is a black spot, on the underneath of her belly, near her tail. When pregnant, this black spot will become darker and grow in size.

Secondly, you can look at the mother’s belly. This one is harder to notice as a female guppy can be bloated for a variety of reasons. Although once you notice a slight bulge, then make sure to keep an eye on it. If your female keeps growing, then your guppy is most likely pregnant!

A female guppy is usually pregnant for an average of 21 to 30 days. If you are trying to identify a pregnant female, make sure you watch both the gravid spot and belly of the female for around 21 to 30 days.


In conclusion, guppies are relatively tiny, around 0.25 inches at birth, and therefore require care and protection. Make sure to look out for signs of a pregnant guppy so that you are all prepared and ready to be a guppy mummy! Removing your guppies from the main tank or adding live plants is an excellent way to ensure your baby guppies mature.