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How Big Do Axolotls Get? [Average Length And Size Guide]

Axolotls are quite the salamander; unquestionably cute and fascinating to observe and take care of. If you are interested in taking on one of these waterborne amphibians, then you will naturally have some questions about them and what to expect – particularly in reference to their size and tank requirements. Here is what you will want to know.

So, how big do Axolotls get? Axolotls typically range from 6-10 inches in length. However, Axolotls can grow much larger than this depending on where they live and how they are kept. Nevertheless, these amphibians generally reach their full adult size between 18-24 months following birth.

Axolotl Size

Fascinatingly, Axolotls have the astonishing ability to regrow segments of the spinal cord, pieces of the brain, and whole limbs if they are injured!

This says a lot about the ability to grow.

It’s therefore quite ironic that they possess comically short limbs and chunky little bodies.

This astonishing regeneration ability really does set them apart, but it also results in more questions when answers when it comes to their resulting size!

So, Let us now take a closer look at the size of the average Axolotl in further detail.

We will also be covering the importance of their tank and diet for ensuring they reach their potential.

So, if you are serious about taking on this smiley salamander, be sure to keep reading to set your expectations and know exactly how to approach their care!

How Big Is A Full Grown Axolotl?

A fully grown Axolotl will usually reach between 6 and 10 inches in length.

This is just an estimation and it is based on Axolotls that are kept in captivity.

Since they will grow in accordance with their environment, some Axolotls have been known to grow up to 18 inches.

However, from a biological perspective, an Axolotl will never actually grow up. This is because they are neotenous.

This essentially means that they never theoretically enter an adult phase of life. In other words, they will retain a number of their juvenile characteristics.

This is unlike most other amphibians, who will lose these when they enter their adult stage.

As such Axolotls never transform into land-living adults who breathe through their lungs.

Instead, their juvenile features such as tails and gills are retained, and they much prefer to live in the water.

How Long Does It Take for An Axolotl To Reach Their Full Size?

It can take between 18 and 24 months for an Axolotl to reach their full-grown size.

Of course, the exact time that it will take will depend on their aquatic conditions and how often they eat.

Sex also makes a slight difference because females take a little bit longer to mature than the males do – usually a difference of a couple of months.

Although they are not fully grown until many months after, an Axolotl will reach sexual maturity around the age of 5 to 6 months.

However, it is not advisable to breed Axolotls until they have reached the age of 18 months and have basically achieved their full-grown size.

How To Set Up The Tank Properly So That Your Axolotl Grows Fully

Since they are accustomed to the waters of Mexico, it takes a bit of work to get their tank set up optimally, and so that they will grow to their full-size potential.

Let us now take a closer look at some of the important factors you will want to get right:


One important consideration is the type of substrate you will use. Axolotls eat by sucking water into their mouths.

If substrate particles get ingested accidentally, Axolotls can be seriously injured or even killed.

So, when you are setting up your Axolotl’s new home, stay away from the gravel.

Instead, fill the bottom with aquarium sand. They also love to dig and play in the sand so this will keep your pet occupied and happy. You can also easily add decorations, hiding places, and plants when using sand.

Filtration System

Since Axolotls are overly sensitive to incorrect water conditions, you will need to have a good filtration system installed on your tank.

They prefer still water so make sure that you choose a filter that will not disturb the flow of water in your tank.

One great option is to purchase an external canister filter that can be fitted with a spray bar.


Since they do not have eyelids, Axolotls are quite sensitive to bright light.

They much prefer low-light conditions like what would be found in their native environment.

Although they will get used to bright light over time, your Axolotl may become distressed and stop eating.

Water Conditions

Maintaining the correct water conditions is critical to the longevity, wellbeing, and health of your Axolotl.

You obviously want your Axolotls to stay healthy and one way to ensure this is having the water in your tank at the correct temperature.

Axolotls need stable temperatures – they do not do well with temperature fluctuations.

Keep your water temperature in the range of 15 to 23 degrees Celsius. Never let the water reach 24 degrees.

When their water is too warm, Axolotls usually become distressed. This can cause reactions like loss of appetite, fungal infections, and possibly death.

Water that is too warm will also increase the ammonia toxicity in your tank and this is very detrimental to Axolotls.

On the other hand, you also do not want your tank water to get too cool. If this happens, your pet’s metabolism will start to slow down.

This will cause them to be unwell and sluggish.

Water PH

The last thing you need to know about is the pH of the water in your tank. The perfect pH for Axolotls is between 7.40 and 7.60.

However, they will tolerate a range of 6.5 to 8.0. The most important thing is keeping the pH stable at all times.

You can buy test kits like this bestseller on Amazon which will enable you to check your water on a daily basis.

If your pH needs correction, you can make adjustments using pH changing kits or salts to bring the pH back to normal levels.

What Kind Of Diet Should I Feed My Axolotl So That They Reach Their Full Growth Potential?

The only thing you need to know is that this species is carnivorous.

When left to their own devices in the wild, Axolotls are known to make a meal out of small fish, insects, worms, and almost anything else that they can fit in their mouth.

This also includes other Axolotls!

However, when they are in captivity, the most nutritional food source is organic nightcrawlers.

Other healthy choices include bloodworms and blackworms.

Like any other pet, Axolotls love to be spoiled. And they absolutely love treats.

Some great choices for treats include lean beef or chicken, prawns, tuna, frozen shrimp, and mealworms.

One thing you need to be aware of is that an adult Axolotl will eat until it is full.

They will usually eat a couple of earthworms every few days and they will turn down a meal if they are still full from the previous one.

Juvenile Axolotls are a little bit different in that they must be fed daily. They will also need smaller pieces of food than what an adult could easily consume.

If your adult Axolotl is healthy, it is possible for them to go for up to two weeks without eating.

However, Axolotls that are younger and still growing should never go for longer than 3 days without having a meal.

What Size Tank Does An Axolotl Need?

Axolotls need a tank that is at least 20 gallons to give them plenty of space to move around and explore.

They also prefer tanks that are at least 2 feet long because they love nothing more than exploring around the bottom of the tank or simply floating on the surface of the water.

Another of their favorite activities is hiding. Make sure that you have various options in the tank so that your Axolotl can play hide and seek!

Axolotls come in a variety of colors and some of them can make it difficult to locate your pet in the tank when they are in hiding mode.

What Is The Minimum Tank Size For A Single Axolotl?

The absolute minimum size of the tank that you should put a single Axolotl in is 10 gallons.

When they are put into tanks that are 10 gallons or less, an Axolotl will adapt to the size of the tank and stop growing accordingly.

When you are considering which tank to purchase for your Axolotl, go with the philosophy that bigger is always better.

Your Axolotl will never complain that they have too much room and you will find that they will grow larger.

If you have or are planning to get, more than one Axolotl, each one will need a minimum of 10 gallons.

So for example, if you have 5 Axolotls, you will need a 50-gallon tank.

Worth noting is that juvenile Axolotls should never be put in the same tank together.

The chances are extremely high that they will be eaten by one of the others.

Once they are fully grown adults it is safe to house them together and it is very rare that they would fight with each other.


Axolotls are not one of the largest amphibians.

This is all despite the fact that they have unique regeneration abilities, they never enter an adult phase of life, and they grow in accordance with the size of the tank they are kept in.

That being said, the average Axolotl owner who keeps one in a respectably sized tank often reports that their salamander reaches between 6-10 inches in length.

While this is the average, they definitely could be larger than this. So, that is something you want to consider.

All in all, an Axolotl makes a fantastic and intriguing pet. Just be sure to do your research and educate yourself as much as possible about their needs.

Looking after them is not overly difficult, but you do need to be able to ensure that you care for them properly and appropriately.

Something as simple as incorrect water conditions, diet, or temperature can prove fatal.

Otherwise, with proper care, you can expect your Axolotl to be with you for up to 15 years.

Related Questions

How Can You Tell The Age Of An Axolotl?

There is little way of knowing the age of an Axolotl outside of knowing their birth date. This is because you cannot judge age by size in this salamander. Different Axolotls will be different sizes at the same age, and their size is largely dependent on their nutrition and the amount of space that they live in and are accustomed to.