How Big Can A Turtle Get? [Size Chart]

The information is current and up-to-date in accordance with the latest veterinarian research.

If you plan to buy a turtle for the first time, you must consider how big it can eventually get. There are different species of turtles, and they can grow to different sizes. Knowing how big your turtle can get is essential for building the right size turtle tank. So, how big can a turtle get?

Depending on the species of your pet turtle, you can expect it to get 2.75 to 12 inches long. However, an adult sea turtle, like the leatherback can reach 6 feet. Land turtles, such as an adult giant tortoise can be over 4 feet. 

Many records show turtles reaching exceptional lengths. You will learn about the biggest and the average size of various turtle species from this article.  

What Is The Biggest Size Of A Turtle? 

There are different kinds of turtle species in the world. They can be categorized into aquatic and semi-aquatic, freshwater and seawater turtles, or sea turtles and land turtles.

Among all the species of turtles, the sea turtles are the largest. They live a long life. Thus, they can get huge in both length and weight. 

The leatherback turtles are the largest living sea turtles. They can grow up to 6 feet on average and weigh 500 to 2,000 lbs. Moreover, some leatherback turtles have reached even 8 to 9 feet!

Sea turtles are bigger compared to freshwater and land turtles. Even the smallest sea turtle like the Kemp’s ridley can get 2 feet long. Here is a list of sea turtle species and how big they can get:

Species of Sea TurtlesAverage Adult Size
Leatherback Turtle6 feet
Green Turtle4.5 feet
Leatherhead Turtle3.6 feet
Flatback Turtle3.2 feet
Hawksbill Turtle3 feet
Olive ridley2.5 feet
Kemp’s ridley2 feet

On the other hand, the largest living land turtles are the giant tortoises. These tortoises can become nearly 5 feet at their mature age and weigh 500 pounds. They live on the Islands of Galapagos in the Indian Ocean. 

Common Pet Turtle Species and How Big They Can Get

You can only keep freshwater turtles as pets. It is illegal to buy sea turtles as pets. As mentioned before, freshwater pet turtles reach a size of 3 to 12 inches according to the turtle species. 

Here is a size chart for some common freshwater turtles that are great as pets: 

Species of TurtleMale SizeFemale Size
Red-Eared Sliders5-9 inches (12.7-23 cm)10-13 in (25.4-33 cm)
African Sideneck Turtle7-10 inches (17.78-25.4 cm)7-12 in (17.78–30.48 cm)
Eastern Box Turtle5-7 inches (12.7-18 cm)5-7 in (12.7-18 cm)
Western Painted Turtle5-6 inches (12.7-15.24 cm)6-10 in (15.24-25.4 cm)
Common Musk Turtle2-5 inches (5-12.7 cm)4-5 in (10.16-12.7 cm)
Spotted Turtle3.5-5.0 inches (9-12.7 cm)4.5-5.5 in (11.43-13.97 cm)
Yellow-Bellied Sliders5-9 inches (12.7-23 cm)8-13 in (20.32-33.02 cm)
Reeve’s Turtle5-6 inches (12.7-15.24 cm)6-9 in (15.24-23 cm)
Wood Turtle5-9 inches (12.7-23 cm)5-8 in (12.7-20.32 cm)
Texas Map Turtle2.5-4 inches (6.35-10.16 cm)5-8 in (12.7-20.32 cm)

 A young turtle can be just a size of a quarter, but as time goes by, it can grow to 12 inches at a mature age. 

So, when you are building a tank for your turtle, you have to keep this fact in mind. One should find out how big a turtle species grows to choose the right size tank. 

There should be 10 gallons of water for every 1 inch of turtle length. So, if you are getting a Western Painted Turtle, the tank should have at least 100 gallons of water, as a female Western Painted Turtle can have a length of 10 inches. 

What Pet Turtle Grows The Biggest? 

As you can see in the chart, the biggest pet turtle species are the Red-Eared Sliders, African Sideneck Turtle, and the Yellow-Bellied Sliders. The females of these species get bigger than their male counterparts. 

For example, an adult Red-eared Slider male turtle can be 5-9 inches (12.7-23 cm) long and weigh 250 to 350 grams. On the other hand, a female can grow 10 inches or more and weigh 550 grams. 

If you have an African Sideneck, you can expect the male turtle to be 7 to 10 inches long during adulthood and the female turtle a few inches more. Female African Sidenecks can reach up to 12 inches. 

Another large size pet turtle species is the Yellow-Bellied Sliders. Although the males remain 5 to 9 inches in length, the females can grow to be 13 inches long!

What Is The Largest Sea Living Turtle Ever Recorded?

On average, an adult leatherback turtle can be 5 to 6 feet long. But what if we say a leatherback turtle can grow even bigger? I recorded a living leatherback turtle 8 feet long and weighing 916 kg (2,019 lbs). 

Also, on 23 September 1988, a male leatherback turtle having the size of 9 feet 5½ inches was found at Harlech Gwynedd beach. Unfortunately, the poor 100-year-old sea turtle was caught in a fishing net and drowned to death.

However, the Wild Trust managed to get the dead specimen not long after. The turtle was perfectly in good condition. The Wild Trust carried the turtle with difficulty to Cardiff at the National Museum of Wales, UK. 

A crane was hired to move the giant turtle. It was so heavy that even a crane struggled to lift it. The leatherback weighed 961.1 kg (2,120 lb)! So, it is obviously a challenge to handle such a large and heavy specimen.  

Although large turtles are not easy to exhibit in museums, the National Museum of Wales took proper care of the giant turtle. They prepared it and put it on display on 16 February 1990. 

How Big Did Ancient Turtles Get? 

Sea turtles have been around in this world since prehistoric times. Yes, turtles existed with dinosaurs! One of the most known ancient marine turtle species are the Archelon and the Protostega. These turtles from the Cretaceous period could grow 10 feet to 15 feet long in their lifetime. 

In 1897, German paleontologist Georg Baur first talked about the fossils of the Archelon turtles and other giant turtle species that lived between 83 million and 72 million years ago in the Late Cretaceous Period. This giant sea turtle species used to roam around the huge sea in North America. 

According to paleontologists, Archelon ischyrios was the largest sea turtle ever excited in the world. Their size could be 4.6 meters or 15 feet, which makes the leatherbacks much smaller. 

How Big Do Giant Turtles Get? 

Apart from sea turtles, land turtles also grow to an extraordinary length. The giant turtles are better known as Giant tortoises or Galápagos tortoises. There are 13 species of Galápagos tortoises found in the Galapagos Islands of Ecuador. An adult giant tortoise can grow over 4 feet long and weigh 450 to 500 pounds.

These tortoises are the longest living vertebrates on the land. They can live up to 120 years. Thus, they become huge during their long lifetime. Besides, it is not surprising to see a Galápagos tortoise over 5 feet. In fact, the largest Galápagos tortoise specimen was nearly 6 feet and weighed 919 pounds!

Do Turtles Get Bigger With Age?

Like any other animal, turtles get bigger with age. But you should expect slow growth. By the age of 4 to 10 years, most turtle species reach their full size. Turtles grow faster during their first 4 or 5 years. But after that, they grow slowly. 

How fast your turtle will grow depends on its species and many other factors such as its diet, habitat, and temperature. Hence, you may find turtles of the same ages having different lengths. 

So, if you want to help your turtle grow faster, arrange a spacious tank with a sufficient amount of UVA and UVB light. Feeding the right kind of food is also crucial. You have to provide lots of protein and vegetables to your young turtles for healthy shell growth.  

Where Is The Biggest Living Turtle In The World? 

As mentioned above, the leatherback sea turtles are the biggest living turtles in the world. These giant marine turtles live in tropical and subtropical oceans and in the Arctic Circle. 

Most sea turtles live in the eastern Pacific, western Pacific, and Atlantic Oceans. Hence, the coastal areas around these oceans are their nesting habitat. 

How Big Do Land Turtles Get? 

Land Turtles or tortoises prefer to live on land more than on the water. Depending on the species, the size of tortoises varies. They can be only 2 inches to 6 feet and ½ inches. 

For example, an adult Speckled Cape tortoise can be only 2.5 inches (6 to 8 cm) long. On the other hand, an Aldabra Giant tortoise measures 4 feet or more. There are also land turtles like the Desert Tortoise that grow to a moderate length of 12 to 14 inches. 

Do Turtles Grow To The Size Of Their Tank?

Many people think turtles grow according to the size of their tank. But this idea is one of the common misconceptions about turtles. People who believe this myth often keep the turtle in a small enclosure, hoping that it will keep the size of the turtle small. But this only causes suffering to the poor reptile. 

Keeping your turtle in a small tank will cause harm to it in many ways. Turtles need ample space to move and swim around. Thus, a small tank will restrict its natural movement and hamper its health. A turtle does not have much chance of survival in a congested or small tank. 

Therefore, you must provide the right size tank for your turtle to live a healthy and comfortable life. 

Also, if you want your turtle to grow fast, keeping them in a large tank is not enough. You have to feed the turtle healthy food and manage the light and temperature to digest the food. It can help the turtle to grow its bones and shells.


So, how big can a turtle get? You should have a good idea about the length of different turtle species by now. If you want to build the perfect habitat for your turtle, you better know its maximum size. Depending on the species, a turtle can grow about a foot long. Hence, keep turtles in a spacious tank to live comfortably. 

About Author

Muntaseer Rahman started keeping pet turtles back in 2013. He also owns the largest Turtle & Tortoise Facebook community in Bangladesh. These days he is mostly active on Facebook.


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