How to Tell the Age of a Turtle (Step By Step Guide)

Out of all of the animals on this planet, turtles are amongst those that live the longest, as they have a pretty impressive lifespan, some species more than others. So if you get yourself a pet turtle, you can expect it to live for quite a good amount of years. 

If you don’t know the exact day the turtle was born, it can be very tricky to figure out the exact year. Your best shot is probably to just take the turtle to a vet or specialist, and they will know exactly what to look for. 

But if you want to try and figure out the age of your turtle yourself, then there are a few methods you can use. They might not be completely exact, but it’s a step towards estimating the approximate age of your turtle. 

Let’s get right into it! 

Different Methods for Telling the Age of a Turtle

We’re going to give you four different methods of telling a turtle’s age. Two of them are fairly easy and simple to do yourself, and two are alternative methods that aren’t as accessible to the average person when figuring out the age of your turtle at home. 

(The easy methods will be 1 and 2, while 3 and 4 will be the alternative ones.) 

METHOD 1: Counting the Rings on the Carapace

This is probably the most common method for figuring out the age of a turtle, and it’s also the fastest to use. This is how to do it:

1. First of all, you need to understand the scute, which is located on the upper shell of the turtle carapace. This is there to protect the carapace from predators and others, and it will have rings on it.

Larger or broader rings develop during the summer when the turtle eats more, and smaller or thinner rings develop during the winter when the turtle eats less. Therefore, you can use these rings to count the seasons, and in turn the years! 

2. Once you have identified the rings, you can start counting them. For every large and thin ring, you have a year, and so you will get an approximate amount of years during which your turtle has been alive. 

However, sometimes turtles will develop rings for other reasons, or rings will become thinner with time, and therefore the number of years will never be exact. It’s just an estimate. 

3. It’s recommended that you count all the rings at least twice, as they can be tricky to see properly. It’s also worth having someone else double-check for you too! And if the total is, for example, 16 rings, then it’s an estimate of 8 years. (As we said, every two rings is a year!) 

METHOD 2: Checking the Size

Turtles will usually grow in size as they age, so an older turtle will be bigger than a younger one. This is why a good way of estimating the age of a turtle is by checking the size, and comparing it to the average size of differently aged turtles. 

To measure the turtle, use a measuring tape from top to bottom, so you’re getting the full length. Your turtle will likely try to move or might even hiss at you, but a nice treat should keep it calm while you check the size. Once you have the measurement of your turtle, compare it to the average size of different ages. Here is a guide:

  • Baby turtles: Both males and females will be between 30mm to 40mm.
  • 5 years old: Males will be between 70mm to 75mm in length. Females will be around 130mm. 
  • 10 years old: Males will be between 90mm and 100mm. Females will be around 160mm.
  • 30 years old: Males will be between 100mm to 110mm. Females will be around 225mm. 
  • 40 years old: Males will be between 100mm to 110mm. Females will be around 230mm. 

It’s important to remember that this guide is not exact, and your turtle could be bigger or smaller at a different age. But it’s a good way to get an estimate. 

Also, once your turtle is fully grown, it will stop growing, after which this method will not be useful for figuring out the age. 

METHOD 3: Examining the Bones

Scientists will use this method of examining the bones to figure out the age of some marine turtle species. The method doesn’t work for all turtles, and the credibility isn’t fully established yet. But it’s a way of getting extra information when forming a more accurate estimate on the exact age. 

The method essentially looks at the rings that form annually in some species of marine turtles, within the skeleton. The method is still being developed, but perhaps in time, it will become a more reliable form of identifying age in turtles! 

METHOD 4: Checking for Signs of Aging 

This is a method that can’t be used with pet turtles, as the signs of aging wouldn’t be as visible. But it’s a very good method for determining the age of wild turtles, within their natural habitat. 

As turtles age in the wild, the carapace starts to wear down and tear. Dents and chips will begin to develop, and the color will fade or darken. There might also be scars or injuries that help pinpoint an age too. Basically, if there are dents or spots on the turtle, it is almost certainly of mature age, meaning it will be between 15 to 20 years old. 

As mentioned, this doesn’t work with pet turtles, because they are so well-maintained that they don’t suffer from worn down carapaces, dents, or scars. 

In Conclusion

The best way to tell the age of a turtle is to know exactly when it was born and to keep track. But of course, this isn’t always possible. So you can either count the rings on the carapace or measure it and use an age chart.

You could also observe for signs of aging, if it’s a wild turtle, or if it’s a specific species of the marine turtle then scientists might want to analyze the bones.