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How Big Do Snapping Turtles Get?

If you are wondering ‘How big do snapping turtles get?’, then we’d like to bring your attention to the Alligator snapping turtle.

These massive turtles can reach a carapace length of 40 inches )101.6 cm) and a mass/ weight of 176 pounds (80 kg) and the largest alligator snapper on record weighed about 249 pounds (113 kg).

Other snappers can get quite large, as well. The common snapping turtle can reach a mass of 35.3 pounds (16 kg) and a length of 18.5 inches (46.9 cm). The South American and the Central American snapper are of the same genus as the common snapper – genus Chelydra – and are similarly sized.

Finally, there is the Suwanee snapping turtle, which is closely related to the Alligator snapper and may weigh up to 200 pounds at maturity.

This is definitely a subject that is worth a closer look. How big do snapping turtles get? Let’s take a look at the facts about these amazing creatures and you can see for yourself!

Growth Rate

A common snapping turtle hatchling is cute - but will get bigger FAST!

When hatched, the snapping turtle is about just 1.14 inches (2.9 cm) in length, although they may range anywhere between .62 – 1.49 inches (1.6 to 3.8 cm). They do not remain this size for long.

Provided that they are healthy and eating regularly, these turtles are relatively fast growers. Take a look at what can happen in just the first 5 years and you’ll see what we mean!

Have a look at our guide on how long snapping turtles live to learn more about their lifespans.

First Five Years

While they generally hatch in the late summer and early fall, if it’s cold outside, then snapping turtle hatchlings will wait and spend the winter brumating (a process similar to hibernation) in their eggshells until it’s warm enough to hatch and get moving.

Over the first year, these cute little guys and gals start getting bigger, increasing in size by about 2 to 3 inches (5.08 – 7.62 cm) in carapace length and during the second year, they’ll grow another inch or two.

At this point, they should measure about 3 to 5 inches (7.62 – 12.7 cm) in size. As you can see, by this time they’re already moderately-sized turtles – with an appetite to match! Larger prey is now required, and the juvenile turtles begin feeding on fish, snails, insects, and crayfish.

During the third to the fifth year, their carapace length will increase from 5 to 6 inches (12.7 – 15.24 cm) to about 8 to 10 inches (20.32 – 25.4 cm). This is the last big ‘growth spurt’ of these turtles and the biggest one they’ll have in their life, but they’re still not done growing.

They will continue to increase in size but at a much slower rate!

Next Five Years to Adulthood

Over the next five years, the snapping turtle will increase by 2 to 4 inches (5.0 to 10.16 cm) and will weigh between 10 to 30 pounds.

Common snappers will keep growing until they reach about 10 to 18.5 inches (25 to 47 cm) in carapace length and 8.8 to 35.2 lb (4 to 16 kg), while alligator snappers will keep growing until they reach about  31.1 to 39.8 inches (79 to 101 cm) of carapace length and 154 to 176 lbs (70 to 80 kg) of weight.

Common Snapping Turtle Growth Range Chart

Age (years)Average Shell Length (cm)Average Shell Length (inches)
02.91.1
18.9  to 12.73.5 to 5
2 – 313.5 to 15.55.3 to 6.1
4 – 611.9 to 23.94.7 to 9.4
1025.410
15 – 4035.6 to 4714 to 18.5

Simplified

AgeAverage Shell Length (cm)Average Shell Length (inches)
2124.7 
204517.7

Alligator Snapping Turtle Growth Range Chart

AgeAverage Shell Length (cm)Average Shell Length (inches)Mass/Weight (kg)Mass/Weight (pounds)
03.81.5
16.35 to 10.22.5 to 40.4 to 0.91 to 2
212.7 to 15.25 to 6
315.2 to 20.36 to 8
520.3 to 25.48 to 10
1025.4 to 30.510 to 124.5 to 15.910 to 35
10 to 2030.5 to 40.612 to 1615.935
4040.6 to over 6616 to over 2620.946
50+40.6 to over 6616 to over 2629 to 8064 to 176 (for males, females remain at 46 pounds)

Factors That Affect The Size of the Snapping Turtles

Common Snapping Turtle (Chelydra serpentina) found on a road near Boise River, Garden City, Idaho, USA
A Common Snapping Turtle (Chelydra serpentina) found on a road near Boise River, Garden City, Idaho, USA. – Source

Snapping turtles kept in captivity tend to be bigger than those found in the wild. This is due to several factors, but mainly it boils down to this: Turtles in captivity have access to more food, better living conditions, and live longer.

So, factors that affect the size of the snapping turtle can be divided into diet, age, living conditions, and sex. Let’s take a closer look.

If you need to pick one up, here’s a guide on how to pick up a snapping turtle, without knowing the right way to do it can lose you a finger!

Diet

The more food the snapper eats on a regular basis, the larger it will grow to be. Both the common snapper and the alligator snapping turtle are opportunistic feeders and excellent predators, so they tend to do well enough on their own in the wild.

The alligator snapping turtle is mostly carnivorous, feeding largely on animal material. It hunts several different animals, including amphibians, mollusks, snails, snakes, worms, crayfish, invertebrates such as insects, water birds, small alligators, and other turtles.

Especially other turtles!

A study conducted in Louisana revealed that 80 percent of the food in an adult alligator snapping turtle’s belly was comprised of turtles. Simply put, these fierce-looking Chelonians have no problem whatsoever eating their Chelonian neighbors!

They also feed on mammals that come close to their aquatic habitat or try to cross it. These mammals include muskrats, nutrias, raccoons, possums, mice, squirrels, and armadillos.

Common snapping turtles are omnivorous and eat a large amount of vegetation, as well as animals. They feed on reptiles including turtles and snakes. They also dine on amphibians, frogs, fish, and invertebrates, and mammals and birds that get close to them are also on the menu!

In captivity, the snapping turtle will eat fish such as mosquitofish, bluegills, guppies, crappies, and killifish. They will also accept worms, insects, and mice. In addition to this, you may also offer plants such as collard greens, elodea, duckweed, water hyacinth, dandelion greens, and water lettuce.

Living Conditions

Snapping turtle in an algae-heavy hiding place
Algae is fine in ponds but turtle tanks should be cleaner!

The snapping turtle needs to be housed in a large tank. They need an 800-gallon tank for subadults and adults and a 100-gallon tank for a juvenile. They are huge — so their tank needs to be big enough to accommodate them comfortably.

The water within their tank needs to be properly filtered. To do this, we recommend a powerful pond filter such as the  VIVOHOME Pressurized Biological Pond Filter.

In addition to a massive tank, they also require adequate heating and lighting, which can provide UVA/UVB radiation. The REPTI ZOO T5 HO Lamp is a good example of one that you can use.

Temperatures within the enclosure should be 75 to 87 degrees Fahrenheit with 87 degrees Fahrenheit being the temperature of the basking spot, and 75 degrees Fahrenheit being the temperature of the water.

For more information about caring for snapping turtles, be sure to visit our snapping turtle care guide when you’ve got a moment – we’ve got lots of information that you can definitely use!

Sex

The sex of the individual goes a long way in determining their adult size. Generally, adult male snappers are considerably larger than adult female snappers and this will be true for all snapping turtles.

Age

The older the snapping turtle is, the larger it will be. These reptiles do not stop growing, but thankfully, their growth rate drastically falls once they reach maturity.

Frequently Asked Questions

How big is the biggest snapping turtle ever found?

The largest snapping turtle on record reached a weight of 249 pounds (113 kg). However, in 1837, a snapping turtle weighing 403 pounds (183 kg) was discovered in Kansas – but this account was never properly verified.

The largest common snapping turtle on record that we CAN verify is an individual known as ‘Big Snap Daddy’. This turtle reached a weight/mass of 90 pounds or 41 kg and just turned 93 years old last year! He lives in Schramm Education Center in Gretna, Nebraska.

Are there large snapping turtles in Asia?

Feral snapping turtles have been found in China, Taiwan (also referred to as Taiwan, China by some), and Japan. Since snapping turtles aren’t endemic to Asia, these are escaped captive-bred specimens or offspring of escaped captive-bred specimens.

What is the world’s largest turtle?

The world’s largest turtle is the leatherback (Dermochelys coriacea). This turtle is also known as the lute turtle, the luth, and the leathery turtle. This marine turtle can reach a mass /weight of 1982 lbs or 900 kg and the carapace length may be up to 8.9 ft (271.27 cm)!

The largest freshwater turtle varies with the source. The alligator snapping turtle is regarded as the largest snapping turtle. The largest alligator snapping turtle on record was a 249-pound (113-kg) snapper.

The Asian narrow-headed softshell (Chitra chitra) is also considered to be one of the largest if not the largest freshwater turtle in the world. This turtle reaches a mass/weight of 550.66 pounds (250 kg) and a length of 75.59 inches (192 cm) according to ADW. With this species, females are larger than males.

Conclusion

There are five species of snapping turtles, but only two of these are well-known and commonly kept as pets. Those two are the alligator snapping turtle and the common snapping turtle. The other three lesser-known turtles are the Suwannee, the Central American, and the South American snapping turtles.

The alligator snapping turtle reaches a weight/mass of 176 pounds or 80 kg and a carapace length of 40 inches (101.6 cm) and the largest alligator snapping turtle on record reached a weight of 249 pounds (113 kg).

The common snapping turtle is smaller, reaching an average mass of 35.3 pounds (16 kg) and a carapace length of 18.5 inches.

The Suwannee snapper is similar in appearance and size to the alligator snapping turtle, while the Central American and South American snappers are similar in appearance and size to the common snapping turtle.

They’re all pretty big, as you can see, so if you’re considering a snapping turtle as a pet, then you’d better get started putting together their enclosure – it’s going to need to be substantial!

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