Alligator Size | How Big Do Alligators Get?

How big do alligators get?

The largest alligator ever captured was so massive that it broke the winch that hoisted it to get an accurate weight. This behemoth gator was a record-shattering 15 feet and 9.25 inches long, weighing 1,011.5 pounds, and it came from the Alabama River in 2014. And then there is the unconfirmed 1890 report of 19 feet and 2 inches long alligator caught in a Louisiana bayou. Alligator size of course can vary greatly, but just how big do alligators get?  

The average size of adult male alligators is 11.2 feet, and for adult females, 8.2 feet. After alligators mature to about four feet, their only predators are other alligators or humans. As long as they remain in excellent health, alligators can continue to grow up to a certain point. 

Now that we know just how big and long alligators can get, let’s have a closer look at this fascinating reptile and see what factors affect its longevity and, subsequently, its size. 

How Big Can Alligators Get? 

The record confirmed alligator size was just under 16 feet long and weighed just over 1000 pounds.  While it’s possible for an alligator, especially a male, to reach these lengths and weights, it’s not common. The average length for male alligators is 11.2 feet, and the average weight is 500 pounds. Older males often reach 15 feet and can weigh over 900 pounds. For female alligators, it’s much less, the average length is 8.2 feet, and the average weight is 200 pounds. Older females can reach 10 feet and weigh 500 pounds. 

Some studies have looked at alligator growth patterns in males and females, and here’s what they found: 

  • When alligators hatch, their average length is eight to nine inches.
  • Both males and females grow at the same rate until they reach about three feet; at this point, the female grows at a much slower pace than her male counterpart. 
  • A male alligator proliferates until it reaches about 11.5 feet or 20 years old.  
  • When a female reaches 20 years, her average length is about 8.5 feet. 
  • There is a point when alligators stop growing; for females, it’s when they reach about 9 feet, and for males, it’s when they get about 12 feet. 

The last detail about when alligators stop growing is a relatively new concept; many scientists believe that alligators and crocodiles continue to grow throughout their lifespan. However, we just don’t have enough data at this point to know for sure. One thing is for certain—the larger the gator, the older it is. 

With baseline information on average alligator growth rates, we can ask what other influences might account for the robust size you see for alligator record-holders in weight and length? 

Other Factors That Affect Alligator Size

  • The sex; males grow faster and larger than their female counterparts. All of the massive alligators are males. Females expend energy on reproductive activities. 
  • The habitat or their environmental conditions can affect their size and their ability to survive. An excellent example of this is that due to human intervention, the alligator was placed on the Endangered species list in 1967. 
  • Food availability is an essential aspect of growth rates and alligator size. Having access to nutrition ensures good health, which in turn provides longevity. 

If an alligator has the optimum living conditions, such as a steady supply of food and protective habitat that encourages growth, the chances of maturing to extreme sizes increases. Most giant gators exist because they have had the best possible living conditions and have survived many other daunting challenges. 

Flooding or predators destroy about 38% of all alligator nests. And from the moment they break out of their shell, they face a perilous journey to adulthood. Small alligators face many predators, from shorebirds to raccoons to fish, and their biggest rival—larger alligators. If an alligator makes it to four feet, its primary concerns for survival are humans and other alligators. 

Human intervention almost decimated alligator populations. In the 1950s, the alligator population reached all-time lows caused by activities including habitat reduction and poaching of illegal meat and black-market goods. The alligator was placed on the Endangered Species list in 1967 and taken off in 1987. 

Repopulating The American Alligator

The recovery was a remarkable success due to the cooperation of private farms, state agencies, and captive breeding programs. The Endangered Species Act prohibited hunting, creating alligator monitoring programs, and the effort between the government and state agencies was nothing short of a miracle. There was a time when the alligator’s survival was questioned. 

The above story is a prime example of how we negatively affect the chances of survival for an entire species and our ability to reshape a promising future for alligators. Because of this recovery, we can observe just how resilient alligators are and how large they can grow. While the alligator recovery effort was a success, there is still concern about habitat loss through development and wetland loss. 

Alligators are vicious fighters, and even more so during mating season, they will consume just about anything, even each other. Alligators are an apex species, and they rank just after another member of their family tree, crocodiles, for having the strongest bite of any land animal, exerting 2,125 pounds per square inch. For comparison, humans have a bite force of 162 PSI. 

Biting and fighting is a way of life, from when they hatch to when they die. The ones that survive to grow into mini dinosaur-like creatures must either have the optimum conditions (and superior genetic makeup) or are very lucky. 

Next, Let’s have a look at how much some of these gigantic alligators weigh. 

How Much Do Alligators Weigh? 

On average, the male American alligator weighs in at 500 pounds and the female at 200 pounds. Males, specifically, are the ones that grow to colossal lengths and weights. 

Let’s have a look at some documented gigantic gators:

  • In Arkansas, in 2012, an alligator was captured weighing 1,380 pounds and was 13 feet and 3 inches long. 
  • The unconfirmed alligator we mentioned earlier from 1890 that was allegedly 19 feet and 2 inches long would have weighed 2,200 pounds—that’s unimaginable. 
  • Florida records document a specimen weighing in at 1043 pounds and was 13 feet and 11 inches long. 
  • This alligator was caught in a pond in Okeechobee, Florida, in 2016 after several cattle went missing from the surrounding pastures and cattle parts were found in the pond. It’s 15 feet long and weighs 800 pounds.  
  • In Texas, an alligator named “Big Tex” was captured in a nature preserve and relocated due to concern about losing its fear of humans. At 900 pounds and 13 feet and 8.5 inches, this gator now lives in a zoo. 
  • The Stokes alligator is the best documented and largest alligator on record. Its length was 15 feet and 9.25 inches, and its weight, 1,011.5 pounds. 

Male Vs Female Alligator Size

In general, your average male alligator weighs about half as much as the biggest alligators ever captured. Female alligators, compared to the males, are more diminutive. 

An interesting point to make is that many of these top-ranking reptiles for size ended up in a protective habitat with few other alligators near them and if there were other alligators present, they were smaller giving them the advantage in holding the territory.

If you look at these giant gators and the environment they were caught in, a pattern becomes evident. Most have a reliable source of food, most lived in a situation where they were the largest predator in their territory and in a few cases the only predator. All were massive and in excellent health. All the right stuff to ensure continued growth. 

The Stokes alligator was found off the beaten path living in a tributary off the Alabama River. The Okeechobee alligator was most likely the only alligator living in the pond and had a non-stop buffet of cows to choose from. Big Tex was in a nature preserve living his best life with a constant source of food and a guess is that there were no other predators even close to his size or strength. 

It would be interesting to have a look at the environment, diet, and competitors of these living, ancient reptiles to see exactly what conditions helped them achieve their status. 

Now that we’ve looked at alligator weight let’s get the details on alligator length. 

How Long Do Alligators Get?

Alligators continue to grow in weight and length as they age. New science suggests a limit to their growth, but we really don’t know how long growth continues. So, it’s conceivable that as we continue to investigate alligators, we learn more about their growth patterns. 

For comparison, let’s review a few details; the average length of the American male alligator is 11.2 feet, and the average length of the American female alligator is 8.2 feet. This baseline information gives us perspective when we look at how long alligators can grow. 

Here are some impressive documented lengths ( however not all have been 100% confirmed ):

  • The Mcllhenny alligator- 19 feet and 2 inches
  • The Stokes alligator- 15 feet and 9.25 inches
  • The Okeechobee alligator- 15 feet
  • Flordia Alligator- 13 feet, 11 inches
  • Big Tex- 13 feet and 8.5 inches
  • Arkansas Alligator- 13 feet and 3 inches
  • Florida Alligator- 13 feet and 11 inches 

These stunning alligator lengths are documented, except for the Mcllhenny alligator,  of how long the American alligator can get. It will be interesting to see how long the Stokes alligator holds the record.

What is the Largest Alligator Ever Recorded? 

This is an interesting question, and answering it depends upon what standards you’d use to qualify “recorded.” Let’s look at the two alligators used in the introduction that are considered the largest alligators ever recorded and see how this information was documented. 

The Mcllhenny Alligator ( Unconfirmed Alligator Size ) 

Consider the 1890 account of Edward Avery McIlhenny and the 19 feet and 2-inch alligator he shot in a Louisiana bayou. 

The story goes that 17-year-old Mcllhenny shot the gator while geese hunting, left it overnight, intending to return with his two companions the next day to “drag” it home. 

Attempts to get the enormous reptile home to verify its length proved futile. It was so massive that the three did not get very far. So, Mcllhenny decided to leave the beast and use the barrel of his shotgun to measure it. He knew the barrel was thirty inches long, and he used it to measure the alligator three times and declared the length to be 19.2 feet long. The only record of this account is word of mouth. 

It’s an intriguing narrative, and while there are many official records of gargantuan gators, the closest in length is three feet shorter. If Mcllhenny had taken the alligator’s head, which was a common practice by naturalists at that time, it could have helped corroborate his account. 

The Stokes Alligator 

Then there’s the Stokes alligator that was captured in a tributary of the Alabama River in 2014. This alligator holds the current size record for length at 15 feet and 9.25 inches long and a weight of 1,011.5 pounds. 

In her first-ever attempt to hunt alligators in Alabama, Mandy Stokes, an experienced hog and deer hunter, was the force behind this endeavor. She and her extended family got this gator in a story as impressive as the alligator’s size. Let’s just say that they managed this feat in a 17-foot skiff. For the nitty-gritty details, here’s the story

When the Stokes family brought the alligator to the check-in station, and Alabama biologists and the Safari Club International (SCI) verified its massive weight and length, the sensation went viral. Stokes managed to get a tag to take part in Alabama’s regulated alligator hunts, so biologists from Alabama Wildlife and Freshwater Fisheries were also present to help with the collecting data. 

The Mcllhenny story is interesting. Unfortunately, there’s no way to verify it, and because nothing even close to that size has even been documented, it’s hard to believe. The Stokes alligator is the largest alligator, verified by modern documentation standards. 

This may be a case where you decide which alligator is the largest ever “recorded.” 

Are Alligators Bigger Than Crocodiles?

For the most part, crocodiles grow larger than alligators. Alligators and crocodiles may share similar physical characteristics, and both are members of the crocodilian family tree, but that’s where their similarities end. If you observe each reptile closely, you’ll notice the variations. 

The significant differences between alligators and crocodiles are color, snout size, and their teeth—if you happen to get close enough to observe the teeth. But what about size? Let’s look at what distinguishes these close cousins from each other and then tackle the question of size. 

Here’s how alligators and crocodiles are not alike:

    • Color- Alligators are a dark green that appears black, and young alligators have yellow stripes. Crocodiles can be lighter shades of green, light grey, or brown, or the color can seem like a mottled grayish-green color. 
    • Teeth- When the snout is clamped shut, an alligator’s upper teeth are exposed. When a crocodile’s snout is closed, the lower teeth are visible. 
  • Snout- The alligator has a broad “U” shaped snout, while the crocodile has a narrow, tapered snout more “V” shaped. 
  • Range- Crocodiles are found worldwide; alligators are only found in America and China. 
  • Temperament- The crocodile is far more aggressive than the alligator. 
    • Movement and Agility- While both are stealthy and fast in the water and manage on terra firma, the alligator is the quicker of the two.
  • Size- Crocodiles are larger than alligators. 

So, there you have it in terms of differences, including size. Crocodiles are reign over alligators in this department. Let’s look at just how much bigger a crocodile is. 

What is the average size of a crocodile? 

We’ve seen some massive alligators so far, but on average, American crocodiles are about four to six feet longer than American alligators. The average size is 17 feet, and the weight is 800-1000 plus pounds, compared to an average male alligator at 11 feet and 500 pounds. 

Of all the crocodiles, the Saltwater Crocodile is king. Record lengths of 23 feet and weights of over 2,200 pounds make the largest of all crocodiles. The also makes the crocodile the largest reptile in the world. The average crocodiles’ size for males is 17 feet, and the weight is 1000 pounds. 

While we’ve seen some very impressive American alligator sizes documented throughout this article, it’s apparent that crocodiles are not only longer and heavier, they are more territorial and more aggressive towards humans. 

Alligators, while still dangerous, are nowhere near as large nor as aggressive as crocodiles. Fortunately, the American crocodile is the only species in the states, and it only lives along the southernmost coast of Florida. And of all the crocodiles, the American is the most docile. The Australian crocodile, followed by the Nile crocodile, are the top two in terms of unprovoked aggression.


In summary, alligators can grow to extreme sizes, not as extreme as crocodiles, but massive nonetheless. The biology of how large alligators can grow is under investigation. Hopefully, with more data, we’ll have a better understanding of their growth rate. We know that the colossal alligators we have observed are males in excellent health and living in optimum conditions.

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