How Big Can Turtles Get?

how big can turtles get

Turtles are nature’s gift to humans. Most turtles belong to aquatic families, and they need water to survive. Depending on the species, a pet turtle can go up to 15 inches or more in size. Female turtles usually grow larger than male turtles.

Sea turtles are usually big, and they need a larger room to swim. For a general understanding, we will focus on pet turtles in this article.  

Before getting yourself a pet turtle, it is important to understand how big they can be in the future. In this article, we will discuss the size of a pet turtles when they reach maturity. We will also help you understand the optimum tank size for your pet turtle.

Related Article: How Long Can Turtles Stay Out Of Water?

How big can a turtle grow up to?

The size of a turtle depends on the type of species they belong to. Generally, a pet turtle is expected to reach a size of 12-15 inches. Along with the type of species, habitat environments also play a critical role in deciding the turtle’s growth. 

It is often seen that pet turtles such as painted turtles, red-eared sliders, box turtles, map turtles, wood turtles, or musk turtles reach a size of 12-15 inches at max. Every species of turtle has an approx genetic size. With proper food and a healthy living environment, you can help your turtle achieve their maximum size. 

It should be noted that the size of a turtle varies in the case of sea turtles. Turtle species that are living in the sea grow at least twice the size of pet turtles. 

How big is the largest turtle?

The largest turtle found in the world is the leatherback turtle. These turtles could weigh between 550 and 2,000 pounds or even more. The size of these turtles goes easily beyond 6 feet. 

The leatherback turtles are listed among the endangered species of turtles. The leatherback turtles have a soft shell rather than a hard shell, like most pet turtles. These animals are extremely slow on land and face difficulty while laying eggs. Leatherback turtles could be found in the north of Canada, the northern pacific ocean, and some parts of the USA. 

The leatherback turtles are omnivorous. While in the sea, they mostly rely on jellyfish and other types of fish for their food. 

How big can a pet turtle get?

A pet turtle can grow to a size of 4-15 inches. However, a turtle’s size could vary depending on the type of species, age, tank size, habitat environment, UV light exposure, or food they eat.

Two turtles of the same species can grow differently depending on their habitats. The most important factor which plays a key role in turtle growth is the enclosure they live in. Your pet turtle must get enough UV light and a basking area in its tank. 

The quality and quantity of food also affect the size of a turtle. There are a lot of packaged foods available online for pet turtles. They contain nutrients for the overall growth of the turtle.

Along with the proper diet, make sure your turtle has a basking area and a UV lamp in its tank. Turtles require UV light for their overall growth. It helps absorb calcium from the food they eat and also strengthen their shell. 

Research suggests the size of the tank could also affect the turtle’s size negatively. Turtles need 10 gallons of water per inch of their size. It is a rough estimation of the water they need for their optimum growth.

How big do red-eared slider turtles get?

Red-eared sliders are medium size pet turtles. Young red-eared slider turtles show brighter green color all over the body with yellow-red color behind the eyes. Their green body color becomes dull as they grow older.

Adult red-eared slider turtles typically range from 5-9 inches (13-23 cm) in length, although females may reach 12-13 in (30-33 cm). Male red-eared slider turtles are smaller as compared to females. Despite the smaller size, male turtles have longer tails. 

If we talk about the life span, these turtles can live up to 30 years if kept in a healthy environment. An adult red-eared slider weight could be easily in the range of 3 to 6 pounds. However, their growth potential depends on several factors such as diet, age, gender of the turtle, lighting system in the tank, and habitat environment. Read a complete list of factors affecting the growth of a turtle. 

Difference between male and female turtles’ size?

The difference between male and female turtles can vary depending on the age and species of the turtle. It could be very difficult to identify the gender of the turtle until they achieve sexual maturity. The size of the turtle is also influenced by the food they eat. The healthier they eat, the better they will grow. 

For red-eared slider turtles, sexual maturity is when their shell reaches a size of 4 inches in length (and at the age of 3-5 years). On the other hand, females are sexually mature when their shell size is about 6-7 inches in length (around 5-7 years of age). 

Females turtles grow larger as compared to male turtles. This trend is common in most turtle species. However, in some species like sulcata tortoises, the female can reach up to 100 pounds, and the male could be 200 pounds or even more. On the other hand, male and female sea turtles grow to the same size without significant size differences. 

Shell size is not a very reliable method for determining the gender of a juvenile turtle. However, for most species, you could differentiate between male and female turtles by their shell size once they reach their sexual maturity.

How much do turtles weigh?

An adult turtle’s weight could range from a few pounds to hundreds of pounds, depending on the species. For a leatherback turtle, the weight could be 550 to 2,000 lbsHowever, these are sea turtles and not the pet turtles which you can keep in tanks.

A fully grown pet turtle red-eared slider can weigh up to 6.61 lbs. Female painted turtles could get a weight of up to 500 grams, whereas male painted turtles could be lesser than 400 grams. Box turtles could reach a size of 4-5 inches, and their weight could vary between 1-2 pounds. On the other hand, map turtles can weigh anywhere between 1 pound to 5 pounds in their adulthood.


If you plan to get a pet turtle, make sure you know which species they belong to. The size of a fully grown turtle could go up to several pounds. It is very important to have a larger tank and proper lighting arrangements for your turtle to attain their maximum genetic size.