Hepper is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

How Big Do Bettas Get? Growth Scale & Ideal Tank Size

Lindsey Stanton Profile Picture

By Lindsey Stanton

betta fish_panpilai paipa, Shutterstock

The Betta fish is undoubtedly one of the neatest fish out there, especially if you are lucky enough to have one in your home aquarium. They are bright and colorful, they have big personalities, and they are energetic too.

Caring for these little guys is really not that hard, but you might wonder how to do so. Another question you might have is how big do Bettas get? This is a question we are going to answer right now, plus a couple of others as well.

divider fish plants 2

How Big Do Bettas Get?

Generally speaking, Betta fish are pretty small creatures. A fully grown Betta fish will be around 2.25 or 5.7 cm inches in length. They may sometimes look a little larger due to their large fins, but 2.25 inches is about as big as they get.

Some have been known to grow as large as 3 inches or 7.6 cm in length, but this is quite rare. Of course, how big a Betta fish grows does depend on various factors like genes, general health, water conditions, and the type and amount of food they eat.

Pink-Betta-Fish
Image Credit: gogorilla, ,Shutterstock

How Big Do Betta Fish Get In The Wild?

In the wild, as mentioned before, Betta fish will generally reach the size of 2.25 inches in length. This is their natural size. The larger ones, the ones that have been recorded to grow up to 3 inches in length, are usually always held in captivity.

Generally speaking, really favorable tank conditions and super nutrient-rich foods provided in-home aquariums can cause Betta fish to grow a little larger than they would in the wild.

Do Betta Fish Grow To The Size Of Their Tank?

This is something that is widely debated. However, there is a fair bit of evidence to support the fact that this phenomenon is true, for the most part at least. Betta fish will usually grow to the size of their tank, but this is not surefire and it does not happen all of the time.

In reality, this only works in one direction. If you have a tank that is way too small for your Betta fish, it will probably stop growing at some point before it reaches its maximum size potential.

The body and genes of the Betta fish might stop it from growing any more once it reaches 1.75 or 2 inches in length. If the tank is too small, this can definitely happen.

However, although Betta fish might grow a little bigger if the tank is much larger than they need, they will not grow much bigger. Having a huge tank might make a length difference of anywhere from 0.1 to 0.25 inches, but usually no more.

Yes, Betta fish might grow a little larger than their average 2.25 inches, but this is not only due to tank size, but also has to do with water conditions and feeding as well.

betta fish
Image Credit: panpilai paipa, Shutterstock

How Big Do Female Betta Fish Get?

The bodies of male and female Betta fish are always about the same size. Female adult Betta fish tend to have smaller fins than the males, thus creating the appearance that the whole female is smaller than the male, but it is really only the fins.

Ensuring That Your Betta Fish Grows To Its Full Size Potential

There are a few things that you can do to help ensure that your Betta fish grows to its full-size potential. Let’s talk about how you can make your Betta fish grow as big as possible right now.

Tank Size

The tank does make a difference here. Some people say that Betta fish only need a 2.5-gallon tank. However, this is the absolute minimum and it is a good way to ensure that your Betta fish stays small.

If you want your Betta fish to grow to its full potential and maybe reach 3 inches in length, a minimum tank size of a 5-gallon tank is recommended (we have also reviewed some good Betta Fish tanks). Simply put, the bigger the better in this case.

The Right Food

Your Betta food also needs the proper food to grow to its full size. Sure, it could probably survive on regular fish flakes and substandard food, but we want the Betta to grow big and healthy, not just to survive.

If you really want your Betta fish to get big, make sure to feed it no more than it can eat in 2 minutes, 3 times per day. Overfeeding fish is a good way to make them sick and hinder their growth, be very careful with overfeeding.

Betta fish also need a fair amount of protein, high-quality protein. Giving them high-quality fish flakes, really good tropical fish flakes, is a good choice. Some freeze-dried foods will do as well. Anything healthy, natural, and full of protein is ideal.

Multi color Siamese fighting fish(Rosetail)(halfmoon),fighting fish,Betta splendens,on nature background
Image credit: panpilai paipa, Shutterstock

A Clean Tank

Keeping the Betta fish tank clean is another great way to make sure that they are healthy and grow big. You should change 25% of the water once per week to remove toxins. At the same time, you should clean the plants, gravel, and other things in the tank a few times per month.

Also, having a good filter that engages in all 3 types of filtration is important too. Finally, you want to keep the tank at the proper parameters.

This includes temperature, pH, and water hardness too. Having some good lights never hurts, and some plants to hide under are good ideas too.

wave tropical divider

Conclusion

As you can see, Betta fish do not get that big, but if you do your best and treat them right, you could see your little Betta grow up to 3 inches in length.


Featured Image Credit: panpilai paipa, Shutterstock

Related Articles

Further Reading

Vet Articles

Latest Vet Answers

The latest veterinarians' answers to questions from our database