Why Isn’t My Turtle Growing?

Turtles are such fun pets. They love to swim, bask, and play. We all want to take the best care of our turtles. But sometimes it’s hard to tell when something is wrong and when something is not. This goes for growth patterns, too. Sometimes it’s hard to tell if they’re growing and if they’re not growing, why not?

Why isn’t my turtle growing? Turtles will usually experience a stunt in their growth because of poor living conditions or poor health. 

In this post, we’ll talk about how to tell if your turtle is growing, reasons why they may not be, and when to take them to a veterinarian. 

Normal Turtle Growth Patterns 

To determine if your turtle has stopped growing it is important to establish how much they should be growing and how big you can expect them to get once they are full-grown.

Of course, there are many types of turtles that one can have and each species has different growth patterns. Generally, however, turtles grow to be around 5 inches. The box turtle, for example, can grow to be 4.5 inches to 6 inches or even 7 inches if they are in the wild. 

How You Can Tell If Your Turtle Is Growing 

Sometimes it’s hard to see if your turtle is growing or not. If you don’t pay attention carefully it can be really difficult to tell if they are stunted in their growth or if they are simply growing very slowly. 

The best way to tell if they’re growing is to measure them every day. This way you can know for sure if they are growing, how quickly they are growing, or if their growth is stunted altogether. 

Different Factors That Contribute to Growth 

There are a lot of factors that contribute to the growth of your turtle and can lend some information as to why your turtle has stopped growing or why their growth may be stunted. 

Diet, basking, age, and genetics all play a big part in their growth rate. If there’s an issue with their growth, it most likely has to do with one of these factors. 

Thankfully a lot of these factors are things within your control. If there is a problem with your turtles growth chances are you can fix it with just some quick alterations in their diet or basking temperature. Let’s talk more about all these various factors. 


Diet is the biggest factor that can affect a turtle’s growth. If your turtle is not getting enough nutrients, its growth will be stunted.  This is why all animals need a balanced diet – to promote healthy growth habits. 

A turtles diet is no different and must be varied to ensure they are getting enough nutrients and vitamins. While each turtle is different, generally your turtle should be getting a varied diet of these food items: 

  • Meat or protein
  • Fish
  • Insects
  • Pellets
  • Worms
  • Vegetables 
  • Green leaves
  • Aquatic Plants

Turtles can find most of their needed vitamins and minerals in their diet. However, some vitamins are more important than others and your turtle may need some supplements added to it. While there are a multitude of vitamins and minerals that help promote growth, calcium and protein are the two big ones that help promote healthy growth, protein being the biggest. 

Therefore, it goes without saying that baby turtles will need more protein in their diets than older ones. It is very important to make sure that your young turtle is eating enough protein to help him grow.

However, there is a fine line between too much protein and not enough. Excessive protein can cause your turtle to suffer from a medical condition called pyramiding. This is when the shell starts to form upward to look like pyramids and is caused by excessive growth.

If you notice that your turtle’s shell is growing too fast for their body, cut down on the protein and balance it more with calcium. 

Calcium is another nutrient that is important for  proper growth. Leafy greens are the way to go if you’re looking to add more calcium into their diet.  If you are worried about your turtle’s calcium intake, there are a lot of helpful resources to make sure they are getting an adequate amount of it into their diet.

Cuttlebone is a very popular product to buy. There are also a lot of powders and supplements you can sprinkle on their food. If you’re worried about their calcium intake, call your vet to ask for guidance. 


Basking is very important for your turtle’s health. And they love it! Basking is important for your turtle’s growth because turtles get UVB rays while they bask. These rays help produce vitamin D for your turtle. Vitamin D activates the calcium within their body. 

As we discussed, calcium is a vital nutrient needed in bone development and growth. If their calcium can not be activated, this will stunt their growth. 

Therefore, it is very important to let them have enough basking time and to make sure they have adequate lighting that emits UVB rays. If you notice that there is a slow-down or complete stop in their growth, check the basking light to make sure it’s working and that it’s emitting the correct amount of heat and light. 


At a certain age, we all stop growing. Turtles are no different. Turtles generally reach full maturity and stop growing anywhere between 5 to 8 years of age. This is also why younger turtles need more protein than older ones – it’s because they still have a lot of growing left to do. 

If your turtle is fairly young or younger than 5 years and you have noticed that they have stopped growing, this is very abnormal and cause for concern. Check to make sure everything is right in their diet and that they are basking enough.

If all of that seems correct, there could be some other explanations such as temperature, activity levels, or illness. 

Normal Temperatures

While basking is an important way to monitor your turtle’s temperatures, it’s important that their water is the correct temperature as well. 

Correct temperature is essential for the growth of your turtle. Without proper temperature, your turtle’s growth could be stunted and this could lead to a variety of other health problems. 

The tank should be around 75 degrees Fahrenheit (85 under basking light). Again, these proper temperatures are imperative towards promoting healthy, normal growth functions. If you notice your turtle’s growth is stunted but are unsure why, double check the temperatures of both the basking light and the water/tank temperature to ensure this is not the cause.

Activity Level

Turtles are known to be very active animals. Between swimming and walking they really know how to burn those calories. But what does their activity level have to do with their growth? 

Their level of activity is an indicator of how fast or how large they will grow. This is because when they have a set amount of calories. Sometimes their calories will go to growth and other times it will go to burned energy. 

If your turtle seems to be stunted consider how active they are. If they are swimming excessively or more than the average turtle consider adding more calories to their diet to give them an extra caloric boost. 


Illness can also stunt a turtle’s growth since illness can stop important growth functions. Here are some common signs that your turtle is sick: cloudy eyes, open-mouth breathing, runny stools, lack of appetite, a swollen face, mucus around the nose and mouth or listlessness.

If you notice that your turtle is suffering from any of those symptoms it’s important to take them to a vet right away as this could be causing your turtle’s stunted growth and is likely a sign of underlying illness or disease. 


Turtles grow a lot in their first years of life. In fact, they continue to grow until they are between 5 and 8 years of age. If you notice that your turtle has stopped growing or that their growth is stunted, it is most likely a result of poor living conditions, poor diet, and a poor temperature or not basking enough. 

Make sure your turtle is getting enough protein and calcium. Protein is especially important since this is the biggest way a turtle can grow. Be wary of overdoing the protein, though, as too much protein can lead to other health issues such as pyramiding.

Basking and correct temperatures is equally important as turtles use proper heat in order to absorb essential nutrients that lead to proper growth. If you still have issues with their growth, consider that your turtle may be suffering from an illness and potentially even going to see a vet. 





I’m Devin Nunn, an average joe that just so happens to have a deep love and passion for everything to do with reptiles. Because taking care of them for the vast majority of my life wasn’t fulfilling enough, I decided to begin educating others about them through my articles. read more...