Skip to Content

How Fast Do Turtles Grow

How Fast Do Turtles Grow

Different turtle species grow at different rates. Knowing how fast your turtle grows allows you to plan ahead. You can safely approximate when your turtle will outgrow their tank.

A lot goes into the growth rate of turtles apart from just genetics. The more you feed your turtle, the faster it will grow. Likewise, if you feed your turtle less, the growth rate will be slower.

Table Of Contents

  1. How Fast Do Red-Eared Sliders Grow?
  2. How Fast Do Painted Turtles  Grow?
  3. How Fast Do Snapping Turtles Grow?
  4. How Fast Do Map Turtles Grow?
  5. How Fast Do Box Turtles Grow?
  6. Factors That Affects A Turtle’s Growth Rate

Providing the turtle with a stress-free environment with the right exposure to UVB/UVA light, the right temperatures, and access to hiding spots will ensure your turtle grows as it should.

While you may be tempted to overfeed your turtle so it grows faster, that isn’t advisable as rapid growth can negatively affect the physical development of the chelonian.

Like people turtles get fat too, and it also isn’t good for them.

Since most freshwater turtles are small to medium-sized, expect a growth rate of about 1 – 2 cm per year.

Growth Rate Of Popular Pet Turtle Species

Here are the growth rates of some turtles popularly kept as pets. These include the red-eared slider, map turtles, box turtles, painted turtles, and snapping turtles.  

How Fast Do Red-Eared Sliders Grow?

Different sized red eared sliders
Red eared slider at different angles

Red-eared sliders grow the fastest within the first few years of their lives. Expect them to grow to around 3 to 4 cm (1.1 to 1.6 inches) within the very first year.

By age 2, they can reach lengths of 6 cm (2.3 inches). By age 3, the red-eared slider should reach a length of 10 cm (4 inches).  By age 4, the slider should reach a length of about 11.5 cm (4.5 inches).

Red-eared sliders are generally mature enough to breed at a length of 10 cm (4 inches) for males and 15 cm (6 inches) for females. They typically reach this length at the age of 5 to 6 years.

It can take about 8 years for red-eared sliders to reach their full length, which is generally between 18 to 30 cm (7 to 12 inches).

Of course, the growth rate varies from one individual to another. Variations are usually by an inch or 2. 

Red Eared Slider Growth Chart In Years

AgeAverage Shell Length (cm)
14
26
310
411.5
5-615

How Fast Do Painted Turtles  Grow?

Group of painted turtles basking
Group of painted turtles basking

Painted turtles (Chrysemys picta) grow fastest as juveniles. These turtles have an average juvenile growth rate of about 12.3 mm (1.2 cm) per year. After reaching sexual maturity at about age 10, the growth rate would have fallen to 1.2 mm (0.1 cm) per year.

Upon hatching, the painted turtle would be just a couple of centimeters in length. By age 1, you can expect the turtle to have grown to around 5 cm (2 inches). By age 2, it would be about 7 cm (2.7 inches) in shell length.

By age 4, the painted turtle can be expected to reach a length of 8 cm and by age 5 around 9 cm (3.1 inches).

Painted turtles usually reach sexual maturity at around age 10. At this age, the turtle would be about 12 cm (4.7 inches) in shell length. However, the turtle doesn’t stop growing. Over the next 10 years, expect the turtle to grow an additional 3 cm.

The final shell length of an average painted turtle is 15 cm (6 inches). However, the size range of an adult C. picta is 10 to 25 cm (4 to 10 inches).

Painted Turtle Growth Chart In Years

AgeAverage Shell Length (cm)
15
27
48
1012
2015

How Fast Do Snapping Turtles Grow?

Two common snapping turtles in the water climbing on each other
Two common snapping turtles in the water climbing on each other

Snapping turtles are widely kept as pets. These turtles are voracious eaters. In captivity, they are prone to overeating and growing very quickly. This is particularly true of captive snapping turtles.

As with many other turtles, snapping turtles grow fastest when young. Of course, each individual snapping turtle will grow at a different rate depending on how much you feed them.

Within the first two years, the common snapping turtle will grow to 12 to 15 cm (5 to 6 inches ) in shell length, on average. Over the next 15 to 20 years, the turtle will only grow an additional 30 to 35 cm (12 to 14 inches) in shell length. 

In all, adult common snapping turtles can reach shell lengths of 45 cm (19 inches) and weights of 40 kg (86 lbs).

Snapping Turtle Growth Chart In Years

AgeAverage Shell Length (cm)
212
2045

How Fast Do Map Turtles Grow?

False map turtle swimming in tank
False map turtle swimming in tank

Common map turtle (Graptemys geographica) are small turtles. An adult male usually measures about just 4 inches. Females on the other hand are much bigger, with adults obtaining lengths of 7 to 10 inches.

Upon hatching, male map turtles have an average plastron length of 3 cm, while females measure 2 cm on average.

By age 1, males grow to a plastron length of about 4.2 cm (1.6 inches), while females grow to a length of 4.4 cm (1.7 inches). By age 2, males’ plastron length will on average be 6 cm (2.3 inches), the same length is true for females as well.

By age 4, expect the male’s plastron to be 7.5 cm (3 inches) in length, with the average female’s plastron measuring 9.7 cm (3.8 inches). By this age, the female should be much bigger than the male.

By age 5, the male would measure about 8 cm (3 inches), and the female should measure about 11 cm (4.3 inches). Males should have reached maturity at age 5 to 6. Females reach maturity at about age 10 and at a length of about 18 to 21 cm (7 to 8 inches).

Map Turtle Growth Chart In Years

AgeAverage Male Plastron Length (cm)Average Female Plastron Length (cm)
144
266
378
47.69.6
58.111
613
78.414
816
918
1018

How Fast Do Box Turtles Grow?

Eastern Box turtle being held in hand closed up
Eastern Box turtle being held in hand closed up

As with the other turtles mentioned, common box turtles (Terrapene carolina) grow the fastest when they are young.

The older they get, the slower their growth rate. During the early stages (between ages 0 and 5), expect the common box turtle to grow at a rate of about 10 mm (1 cm) a year.

Between ages 5 and 10, expect the turtle to grow at a rate of just 8 mm (0.8 cm) per year. From age 10 to 15, expect the turtle to grow at a rate of about 2.5 mm (0.2 cm) per year. 

Hatchlings have a carapace length of about 2.5 cm (1 inch). Expect the turtle to grow steadily over the next 5 years. By age 5, the chelonian should have attained a carapace length of about 7.5 cm (3 inches).

This steady growth should continue over the next 5 years. By age 10, the common box turtle should have attained a carapace length of about 12.3 cm (4.8 inches).

Growth will slow down significantly from here with the turtle growing a few additional centimeters over the rest of its life.

By maturity, which should be between the ages of 7 and 10, expect the turtle to reach carapace lengths of 12.7 cm to 15 cm (5 to 6 inches).

Box Turtle Growth Chart In Years

AgeAverage Shell Length (cm)
02.5
57.5
1012.3

Factors That Affects A Turtle’s Growth Rate

Healthy Diet

You can never underestimate the importance of a healthy diet. If you want your turtle to grow at the right rate, then you have to feed them accordingly.

And you can’t feed all turtles the same diet. What you feed your turtle should be determined by the species. Turtles can be herbivorous, omnivorous, or carnivorous.

You need to do your research. For instance, painted turtles require a diet with a protein ratio of 30 to 40 percent, while box turtles require a diet with a protein ratio of about 60 percent.

Also, juveniles generally require more protein than adults do. For example, box turtle hatchlings require a diet with a protein ratio of 70 to 75 percent. 

Also, a strict feeding schedule should be maintained. While most juvenile turtles need to be fed once a day, most adults must be fed about twice a week.

Genetics (Species/Subspecies)

Different species and subspecies grow at different rates. Similarly, two turtles of the same sex & subspecies fed the same diet and kept in the same habitat may grow at different rates.

Check our guide to determine your turtles gender.

Each individual turtle is unique just like humans. Also, different species and subspecies grow at different rates. For example, at age 2, the average common snapping would have attained a length of 12 cm.

Compare this to a red-eared slider that will only reach a shell length of 12 cm at age 4.

Environmental Conditions

Maintaining conditions such as UV exposure, water quality, and quantity, enclosure space, hiding spots, basking spot, and temperature are all important to successful growth. The right amount of UV exposure ensures that the turtle grows at the right rate and as it’s supposed to.

Lack of UVB and UVA can lead to shell pyramiding and metabolic bone disease. Clean water ensures the turtle remains healthy and that in turn influences growth.

Enclosure space is also very important. If the turtle’s living quarters are too small, it hampers growth. 

Keeping the turtle healthy and stress-free will allow it to grow at a steady rate.

Conclusion

Knowing the growth rate of a turtle allows you to plan ahead. As a rule of thumb for every inch, you need to increase the turtle’s tank capacity by at least 10 to 15 gallons.

With this in mind, you can easily determine how quickly a turtle will outgrow its tank. Alternatively, you can also choose the tank size for when the turtle’s eventual length.

The growth rate can also help you approximate when the turtle will be mature enough to breed.

However, just like humans individuals, turtles that belong to the same species may grow at different rates. In this article, I approximate the growth rate.

As such your turtle may grow slower or faster than stated here. Regardless, the information should give a fair idea about what to expect.

If you have any information or questions, kindly leave a comment.

Click to rate this post!
[Total: 2 Average: 5]

Sharing is caring!

Jennifer McConnell

Monday 29th of March 2021

Thank you, very informarive!