Turtles are no doubt one of the longest living animals in the earth. In fact, these are so long living that when you bring them at home, it is often a lifelong commitment to pet them. And it might well happen that you might need to prepare a will separately for your favorite pet turtle after your demise.

So, how to tell the age of a turtle for which you will make such a length commitment? Today I will discuss the best possible ways to determine the turtle’s age. However, you must understand that there’s no established method that can precisely figure out the turtle’s age.

The following two methods will only help you assume the turtle’s age with an approximate measurement. The only way to accurately determine a turtle’s age is to see it born in front of you. But it is a rare event that only a few lucky humans can observe.

How To Tell The Turtle’s Age In Two Easy Methods

Scientists and turtle owners mainly follow two methods to determine the age of a turtle. These two methods are-

  1. Counting the rings on the carapace or upper shell of the turtle
  2. Comparing the turtle size with another one

Now, I will discuss these two methods with details.

Method 1: Counting the turtles rings on the carapace

This is an established method to find the turtle’s age in a quick time. When you look closely at the scute of the turtle carapace or upper shell, you will see several rings on it. In this method, you will have to count them to determine the turtle’s age.

Step 1: Understanding the scute

When we want to find out the turtle’s age by counting the rings on the scute, you should at first understand the real meaning of the scute. It is located right on the upper shell of the turtle carapace. Its primary function is to protect the carapace from external dangers such as predators and other natural phenomena.

You will see two types of rings on the carapace. The broader and prominent rings suggest sufficient feeding sessions during the summertime. On the contrary, the smaller and less-prominent circles indicate winter time when the turtle had to eat less than its necessity.

Step 2: Counting the rings

Once you have understood the real meaning of turtle carapace and the rings types, it is time to count them correctly. You should understand that turtle grow such rings due to various reasons. For instance, the narrower rings might develop during the feminine time. So, even after counting the rings correctly, you won’t get the actual age.


Furthermore, you must realize that not species will have the same colored rings. Also, it varies according to their age. For instance, red eared slider babies have prominent dark-green rings. As they grow, the color of the rings starts fading away.

When the red eared slider reaches two years of age, these rings will transform into brown color. It might make the ring finding process a bit tough for you.

Step 3: Determining the turtle’s age

After you have counted the number of the rings on the turtle carapace, note them down on a notebook. I suggest you recheck the counting second time to make sure that it is correct.  You know that turtles have two types of rings, broader and narrower ones.

Since turtle carapace has two types of rings, you need to divide the total ring counting by two. For instance, if a painted turtle has 16 rounds on its carapace, we get 8 after dividing it by two. So, the actual age of the turtle is 8.

Method 2: Checking turtles size

The size measurement method to determine the turtle’s age is mostly used if your turtle is already grown up. Also, this method is pretty easy to apply. All you have to do is to measure the turtle’s age using a measuring tape correctly.

You must measure the turtle length from top to bottom. Sometimes the turtle may hiss or frequently move during the measuring time. If you face such challenges, I suggest you tempt the turtle with its favorite treat.

Once you have measured the turtle length properly, you will need to compare it with a chart to find the right age of it. The chart is given below for your help.

AgeMale LengthFemale Length
Baby turtles30mm to 40 mm30mm to 40 mm
570mm to 75 mm130mm
1090mm to 100mm160mm
30100mm to 110mm225mm
40100mm to 110mm230mm
50100mm to 110mm235mm

Caution: This is an approximate chart not scientifically established. Also, it might vary from one turtle species to another. Hence, it is suggested that you check for the detailed diagram for the specific turtle species on the online. It will help you better determine the turtle’s age.

Also, the length of the turtle is known as plastron length too.  Note that once your turtle has reached its full size, this method won’t likely work effectively.

Two Alternative Ways To Determine A Turtle’s Age

Apart from the two established methods described above, you can also figure out the turtle’s age with two alternative ways. Although these methods are still not made valid by the turtle owners, you can even take the help of them to determine the turtle’s age accurately.

How To Tell The Age Of A Turtle

Examining the turtle bones:

Scientists have recently started to examine the turtles’ bones to find out the age of sea turtles. However, I don’t recommend the method for average users since it is incredibly challenging.

This method is called as skeleton-chronology. Scientists have found that the sea turtles develop annual rings. Scientists count them to determine the sea turtles’ age.  However, the credibility of the method is not yet accepted by most scientists since it generates mix results.

For instance, the member of “Non-profit Sea Turtle Conservation Organization” Dr Brian Wallace doubted the credibility. He said that although the method worked fine for some sea turtle species, it didn’t come out suitable for other species. Sea turtle such as Kemp Riddle shoed good results in this method.

Observing the visual signs of ageing:

This method of determining turtle’s age is mostly applicable to the wild turtles. It doesn’t work fine for pet turtles.

In the wild habitat, turtle’s color and carapace condition will help you to determine its maturity instead of finding its age correctly. As turtles grow in the wilderness, its carapace will start showing signs of wear and tear gradually. It will even develop dents and chips with age.

You can see scars on the legs and heads of the turtle even if the plastron or carapace appears smooth at first glance. If you see such spots or chips and dents on the turtle body, the chances are high that most likely the turtle has achieved its maturity.  So you can assume that the turtle is between 15 years to 20 years.

Since pet turtles live happily in a well-maintained aquarium or pond, it doesn’t go through such challenging conditions. So, you won’t see the scars, dents and chips on its body. Hence, it limits you from finding the turtle’s age by observing the sign of ageing in the captivity.

Finding the age of red eared slider turtle:

Red-eared sliders are definitely one of the most popular pet turtles in the USA and worldwide. These turtles have an average of 50 years of life expectancy. If you don’t know accurately when it has been hatched, you can’t determine its exact age.

However, the following tricks might help you with the cause.

  • A baby red eared slider turtle will feature a bright color. It will have bright yellow markings on the dark green carapace. Furthermore, it remains the same for the first year of the turtle birth. Nonetheless, it starts fading away as the turtle grows older. By the time, red eared slider baby reaches two years, and you will see its carapace turning into brown color.
  • You can also measure the carapace length to find out the exact age of the red eared slider. For instance, a newly hatched turtle will be less than a thumb in length. It will be around 4 inches of measurement by the time it reaches 2 years age. A fully grown turtle will have a carapace length of about 10 inches to 12 inches.
  • Finally, you can observe the front and back of the red eared slider to determine its age. After a red eared slider reaches 2-years of age, you will see the development of tail and claws in its body. When it comes 3 years old, the nails start transforming intro prickly and sharpened ones. Finally, the claws get shorter as the turtle reaches its maturity.

Determining the age of a painted turtle:

Painted turtles are also as popular as the red eared sliders in the USA and across the globe. However, finding the right age of painted turtles isn’t as easy as of the red eared sliders.

  • Turn the painted turtle upside down. The turtle may hiss at you or even try to bite you, while you turn it upside down. These turtles do so since their belly is the most vulnerable part of their body and they dislike being upside down.
  • Now observe the left or right abdominal section of the turtle plastron. The abdominal area is located in the middle of the plastron and on the lower half. On each abdominal section, you will find 8 separate portions.
  • Count the rings on one side of the abdominal section. The number of circles will tell you the correct age of the turtle. For instance, if you see 6 rings on the abdominal part, the turtle is most likely five years old.

How To Determine the Age of Box Turtles

Well, by now, I think you already know how we are going to determine the age of a box turtle. Watch the video and it will be clear to you –

Some Fun Facts About the Turtle’s Age

Generally, people believe that turtles are the longest living animals and may easily live for 300 years. However, it isn’t a reality. Until now, scientists haven’t found any residing turtle as old as 300 years, not even 200 years.

In the wilderness, a turtle might live around 80 years to 100 years. But in the captivity, it will live slightly longer. It happens because, in the detention, turtles don’t need to search for food. Also, owners take proper care of them with the right food. Furthermore, in captivity, turtles are free from the fear of predators and natural challenges.

All these reasons count for the longevity of the pet turtles slightly. Until now, Jonathan is the longest living turtle ever recorded. It was born in 1832 and lived for the next 189 years.

Wrapping Up

Until now, there has been no well-established method to determine the age of a turtle accurately. Yet, we have found two ways to tell the turtle’s age. While most turtle owners prefer counting the rings, some love comparing the turtle size with the chart.

We leave the decision up to you. Also, we suggest you take help from the expert turtle owners to determine its age accurately when you want to buy one actually.

Similar Posts