How Fast Do Turtles Grow?

how fast do turtles grow

Turtles are very different as compared to other pets. Turtles grow at a much slower rate than humans. These little animals can live more than 100 years in general, so their growth is also slow. Genetics, type of turtle, quality and quantity of food, and their habitat are the most common factors that influence the growth of a turtle.  

For pet owners, turtles’ size is always a topic of debate. They often discuss with other pet owners for finding answers to some common questions regarding the growth of their pet turtle. As a turtle owner for the past many years, I have also come across many such questions in my mind. 

How long does it take baby turtles to grow? Do turtles grow according to tank size? What are the factors that affect the turtle’s growth? We will try to find out answers to these questions in this article. So let’s take a closer look at turtle’s growth cycle and factors affecting their growth. 

Related Article: Do Turtles Have Feelings?

How long does it take for a turtle to grow?

Depending on their species, Turtles can take 5-10 years to grow to their full size. Various factors like the species of the turtle, nutrition and living environment affect the growth of a turtle. Turtles grow at a much faster rate in the initial 5 years, and then their growth slows down but continues till they attain their maximum size.

Turtles don’t have a linear growth rate. At different times of their life, they grow differently. The type of species is a major factor that decides how much time your turtle will take to grow or the size of the turtle in its adulthood. 

Turtle hatchlings have almost the same size, but their growth rate varies from half an inch annually in red-eared slider turtles to a few inches annually in sea turtles. 

Turtle growth is a major concern for pet owners for deciding the size of their tank. As a general rule, every inch of turtle shell requires 10 gallons of water. This measurement is for the minimum capacity of the tank in which you are planning to have a turtle.

Turtles are very sensitive animals, and changing their habitat can cause them stress. It is not recommended to change their tank frequently; rather, you should build a larger tank so your turtle can live there for many years happily.  

Related article: How Big Can Turtles Get?

Do male or female turtles grow faster?

Female turtles grow at a much faster rate as compared to male turtles. Not only the growth rate, but the female turtle also gets slightly bigger than the male turtle. 

The size of the turtle is often used in identifying male and female turtles. However, the size difference in male and female turtles may not be obvious until they reach their sexual maturity. Female turtles often are larger than male turtles, but the size difference could vary depending on the turtle species and their diet. 

Sea turtles, both male and female, grow to the same size, and it is difficult to differentiate between male and female sea turtles by seeing their shell size. 

How fast do red-eared slider turtles grow?

Red-eared slider turtles are the most common pet species of turtle. These turtles reach their maximum size in approx 8 years. The Red slider turtle of under 6 months of age reaches a size of 1.5 inches to 3 inches. In the starting few months, these turtles have a green shell. With growing age, their shell color changes to brown and black. 

By the time they hit the 6 months to 2-year mark, they attain a 4-8 inch length with dark green and brown shell color. 

By the time they attain 2 years of age, a red-eared turtle got a shell size of 4 inches to 12 inches. At this point, they start to develop a much browner and black shell. These turtles generally are ready to breed once their shell size reaches 6-8 inches. 

Do turtles grow according to tank size?

The environment in which you have kept your turtle plays a critical role in the overall development of a turtle. Turtles are aquatic animals, and they usually need a large space to walk and play within. 

If you have a pet turtle make sure you keep them in a large tank for faster growth. I have personally seen small tank turtles growing much slower than other turtles of the same age. Smaller tanks mean fewer areas for your turtle to walk or play; this will stunt their growth due to inactivity. 

If you put a full-grown turtle of 12-13 inches of size in a 10-gallon water tank, it is as stupid as keeping an elephant in your bedroom. The growth of a turtle depends on several factors. Just like humans, their physical activity impacts their growth hormones. 

According to some studies, the turtles living in the wild tend to grow faster than pet turtles. They have a larger area to explore or hunt, which makes them way more active than pet turtles. 

Factors that affect a turtle’s growth rate

As mentioned earlier, a turtle’s growth rate could be influenced by several factors. Some of the factors we are mentioning below:

Environmental factors

Turtles are extremely sensitive animals. Though they don’t have emotions like humans, they do feel fear, stress and depression. Turtles, when not kept in an adequate environment, start feeling stress. In stress, turtles usually cut off their daily activities and stop eating at all. 

A pet owner needs to give their turtle a comfortable environment. Make sure your turtle is feeling safe and comfortable in its tank. Some ladder or other props make their tank a little interesting for them to explore. The happier the turtle better they can grow.

Secondly, as turtles belong to the cold-blooded family, they cannot maintain their body temperature. Instead, they tend to take up the temperature of their surroundings. During the cold season, they hibernate to survive climate change. The cold season affects their growth rate the most. With proper UV lighting and a warmer pond, your turtle can grow much faster than those in cold ponds. 

Quality and quantity of food

A healthy diet is one of the most important factors which decides the growth of a turtle. There are plenty of turtle foods available in the market which you can try for your turtle. These foods are full of essential nutrients and proteins which helps your turtle to grow. 

The Nutritional requirement of a turtle varies during its growth age. It is required to supply your turtle with quality food with adequate quantity. Turtles, when fed more, grow better than others. Although I don’t recommend giving your little champ too much food, quality food should be the focus to attain their maximum potential height. 

Turtle’s genetics and species

Different species of turtles grow differently. Also, genetics plays an important role in the growth of a turtle. Two turtles of the same sex can grow differently depending on the type of species they belong to.


Turtles take time to grow. They usually live a long life, so they have been designed to grow slower than other animals. If you have pet turtles, make sure you keep them in a big tank rather than a small tank. Bigger the tank, the better it will be for your turtle to play and do other physical activities. 

Like humans, turtles too grow at a much faster pace when they do a lot of physical activities. Besides tank size, other factors such as genetics, type of species, quantity and quality of food, heating arrangements, and proper exposure of UV lights play a significant role in the overall growth of the turtle.