How Big Of A Tank Does A Turtle Need

Larry Mills
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Aquarium Sizes for Different Types of Turtles

For more information about the size requirements for turtles according to their species, please refer to the chart below.

It's best to go for a tank that is somewhat larger than what's recommended. A minimum of 15 gallons of tank space is required for one small soft-shell turtle (also known as a swimmers) while the largest species, such as the alligator snapping turtle, requires a very large aquarium of up to 200 gallons.

  • The minimum tank sizes are for turtles that are going to be kept in community tanks, or tanks with other turtles and other non-turtle pets.
  • If you are planning to keep aquatic turtles, like red-eared sliders, please keep them in at least a 30 gallon tank, or bigger.
  • Bigger tanks mean better quality of life for your reptile. It means they have more room to move around and less stress to deal with.
  • Bigger tanks are also easier to maintain, which means you can spend more time watching your animal and less time messing around with the cleaning.
  • Talk to your retailer/breeder about special requirements for your turtle’s care.
  • Take into consideration the size of turtles when designing your habitat! A great naturalistic setup will appeal to your turtle, and give you plenty of room to add an array of other things that can enrich the animal's life.

Aquatic Turtles

The aquatic turtle is just one of the many turtles that make up the turtle family. The turtle contains many different types of turtles which include aquatic, terrestrial, and semi aquatic. These turtles are found in water bodies.

The aquatic turtles are mostly found in water bodies. They are aquatic animals that live in water. The aquatic turtles have special adaptations that help them survive in water.

They have lungs, flippers, and webbed feet which allows them to swim. Turtles have the ability to hold their breath for long periods of time under water so that they can move from one water body to another.

These turtles have a shell which protects them from dangers. The shell also plays a significant role in the movement of aquatic turtles. The shell is flexible hence the reason why the turtles can move around easily.

Land Turtles

Land turtles have different needs than aquatic turtles. Aquatic turtles are kept in small tanks, while land turtles are allowed to roam around. The best way how to determine how big a land turtle enclosure is depends on the type of turtle you choose.

In general, for a small land turtle, an enclosure with about 5.9 square feet is sufficient. Native turtles need a much larger enclosure. Native turtles need an enclosure of about 45 square feet, which is about 5.5×7.5 ft.

Aquatic turtles would be suited for a 30 gallon tank that is at least 18" high. Also, a hospital tank can be kept in the house during the winter, and then moved to the outdoors in the summer. The hospital tank could be half of a 55 gallon tank. A full 55 gallon tank can house one or two toddlers.

Contrary to popular belief, turtles do not need a basking spot to bask in, but they often need to soak in water. The basking spot should be a temperature between 85 and 95 degrees Fahrenheit.

Breeding Turtles

A turtle or tortoise will lay their eggs in late springtime. The average days to lay eggs is approximately 60 days from the moment the pair are brought together to breed. Be aware that the female will need a lot of energy and protein in the form of live or frozen insects to prepare her body for laying eggs.

Tortoises will need a nesting area that is kept neat and dry. There should also be a warm area that does not get direct sun. Make sure the area next to the warm area is kept dry so when the eggs are laid they can be easily found.

You will soon discover that your turtle or tortoise is laying eggs when there will be a noticeable temperature change between the warm area and the cool area. It is also important to keep the male and female separate after laying eggs because many species will hide their eggs and the male cannot help them protect them.

The average incubation period is usually 60 to 120 days depending on the species.


To provide your good turtle with the best care possible, the first thing you need to do is select a good sized tank.

Turtles are aquatic and they need a suitable tank to live in. The best size of a tank for turtles is usually between 10 and 20 US gallons per inch of the turtle’s shell length.

The table below will help you calculate an appropriate tank size for your turtle:

  • Measured Shell Length (Inches)
  • Appropriate Tank Size (US Gallons)
  • Turtle Size

1 – 1.5 inches

Tall, cardboard box.

5 – 2 inches

30 US Gallons

5 – 5 inches

60 US Gallons

7 – 7.5 inches

75 US Gallons

8 – 8.5 inches

90 US Gallons

9 – 9.5 inches

100 US Gallons

5 inches +

How Much Water Should Be In A Turtle Tank?

Turtles, especially the aquatic varieties, do not need a large aquarium. They don’t swim around much, and this inactivity means they don’t need that much space to swim around in. They’re more likely to spend their time in the same small area.

If you have a specific size aquarium in mind, check out these requirements for the most popular types of freshwater turtles:

Painted turtles need a tank that is 22 inches long by 12 inches tall by 16 inches wide.

Loggerheads need a tank that is 25 inches long by 19 inches tall by 12 inches wide.

Cooters need a tank that is 20 inches long by 14 inches tall by 18 inches wide.

So, if you have a smaller aquarium of 20 gallons or more, you have a couple options to provide water your turtle.

You can:

Divide the tank in half with a partition.

Put a regular plate on the bottom of the aquarium and put more water in the back than in the front, so your turtle can go into the back on the plate and be in shallower water.

Place a ramp on the side of the aquarium so your turtle can get onto the plate from the aquarium’s side.

Can Turtles Climb Out Of Tanks?

Turtles are powerful creatures and with a little practice, they can get out of a tank faster than you can imagine. While it is easy for them to climb out, it is not so easy for them to get back in the water.

Turtles can drown in water, but it is a long process especially in a well ventilated environment. They can live for a couple of days without eating but they cannot live more than three days without water. They may even suffer serious ailments and die in just three days without water.

So, simple guidelines on taking care of your turtle and keeping it safe from harm are important.

Ensure your turtle is always in a 1-gallon tank or larger. A 10 -gallon tank is preferred to a 1gallon tank for one turtle. The 1-gallon tank is suitable for dwarf species of turtles.

Always keep the tank with sufficient water and indoors. Keep the tank away from sunlight in case it gets hot or cold.

Always monitor if the turtle swims towards the water. If it does, ensure the turtle has a ramp to enter the water.

Turtles may climb out of tanks if they are feeling overcrowded, to escape, or to get closer to the heat source. The tank should have a ramp or steps leading into the water to eliminate the possibility of drowning.

Avoid getting a tank that does not have a top.

How Many Turtles Can You Put In A Tank?

We have been asked several times on the turtles forum, “How many turtles can you put in a tank?”

The answer to this question is not cut and dry. It really depends on several factors like the size, age, and species of turtle.

Different species of turtles have different habitat requirements. The size of the tank and what needs to be in it should also be taken into consideration. If the tank is too small, the turtle may get aggressive or territorial and start to show signs of stress and aggression.

Basically, you need to size the tank so that it has enough room for all the turtles to move away from each other.

A general rule of thumb is:

  • Put only 2 baby turtles (of the same species) in a 20 Gallon tank
  • Put only 2-3 turtles that are 1-2+ years old in a 20 Gallon tank
  • If you are going to keep more than 2 turtles together, you need a larger tank of at least a 40 Gallon

For a more detailed discussion see: How To Set Up Aquariums For Turtles And Tortoises.

Do Turtles Stay Small In Small Tanks?

A 20 gallon tank with a lid is adequate for hatchlings, but not really for adult turtles. An adult turtle really needs a tank with at least a 50 gallon capacity.

Would you feed an elephant daily with a daily portion of food? No, so why would you do the same with your turtle? Large turtles need large tanks.

A big tank is not only required for an adult turtle, but also because large turtles are messy. While small turtles do not produce much waste, bigger turtles will definitely make your hands go green when scrubbing the tank. So, better be prepared.

The size of the tank you need depends on the type of turtle you have. The bigger the turtle, the bigger your tank needs to be.

The adult animals grow so big that the average person can’t fully appreciate the magnificent size of the turtles. So, as a general rule, provide an adult turtle with a tank that is at least twice as long and wide as he or she is big now.


You can use the steps we listed above for choosing a turtle tank to pick a suitable tank, but you still need to check the dimensions of the tank and the capacity to make sure it is big enough for your turtle.

Here are the minimum tank size requirements for some of the common species of pet turtles:

River cooter: 20 gallons

20 gallons Painted and snapping turtles: 10 gallons for baby turtles, 30 gallons for adults

10 gallons for baby turtles, 30 gallons for adults Red-eared sliders: 10 gallons for baby turtles, 30 gallons for adults (with filter and thermometer)

10 gallons for baby turtles, 30 gallons for adults (with filter and thermometer) Box turtles: 10 gallons

10 gallons Wood turtles: 10 gallons

10 gallons Map turtles: 20 gallons

20 gallons Blandings turtles: 20 gallons

For example, a 10-gallon tank is too small to keep a red-eared slider, which can grow to 11 inches long. At least, junior red-eared sliders need at least a 30-gallon tank.

Recommended Reading

The general rule of thumb for deciding how large your turtle tank should be is 10 gallons per inch of turtle. Of course, it’s always better to provide a turtle with a larger home.

You want to make sure that the tank is large enough that your turtle can swim around in it comfortably, but not so large that it will become bored without enough to do.

Along with the general rule of thumb, there are some other considerations to think about when choosing turtle tank size, such as whether your turtle is an aquatic turtle or a land turtle and the room you have available.

Aquatic Turtles Need Larger Tanks

When you have a aquatic turtle, you need to make sure that the tank is large enough to provide the same swimming space that an aquatic turtle gets in the wild. You don’t want to give your turtle too little swimming space, as this will make your turtle too lethargic. It will also leave your turtle without enough room to get away from you and potential predators.

You should have at least 50 gallons for a medium-sized aquatic turtle and at least 100 gallons for a large one.