Jackson’s Chameleon Size | How Big Do Jackson’s Chameleons Get?


How Big Do Jackson's Chameleons Get?

A Jackson’s Chameleon is one of the larger chameleon species. That said, chameleons in general are not very large lizards. A Jackson’s chameleon size depends on a few factors including sex, health, and environment. But on average how big does a Jackson’s Chameleon get? 

Jackson’s Chameleon’s size ranges from nine to thirteen inches, with males tending to be larger than females. The full size of a Jackson’s Chameleon is determined by several factors such as nutrition and housing. 

Keeping Jackson’s Chameleons in good growing conditions can help them achieve the healthiest size possible. Read on to learn more about the size of Jackson’s Chameleons and how to make sure they stay healthy as they grow. 

How Big Do Jackson’s Chameleons Get?

When they reach their adult size, most Jackson’s Chameleons fall between nine and thirteen inches. But when Jackson’s Chameleons hatch, they’re only around two to four inches in length.

Females tend to be the smaller of the two sexes, with most Jackson’s Chameleon females falling between seven and eight inches on average. 

Jackson’s Chameleons will attain all of their adult growth within the first ten to twelve months of life as they sexually mature.

The reason that chameleons grow so quickly is that they are vulnerable to many predators in the wild at their smaller juvenile size. 

Chameleons are also designed to eat as much as possible during this development to help them put on growth.  Once Jackson’s Chameleons reach sexual maturity, growth slows and eventually stops. 

Size Differences Between Male and Female Jackson’s Chameleons 

While Jackson’s Chameleons generally have a size difference between males and females, there are also specific parts of the chameleon anatomy that are directly related to size and sexual dichotomy.

Here are the two major size differences between males and females: 

  • Horn size: Male Jackson’s Chameleons have the stereotypical three horns that give them the reputation of being “mini triceratops,” but the female Jackson’s Chameleon only has one horn or none at all. This is an easy way to distinguish between the two sexes.
  • Spike size: When looking at a male and a female Jackson’s Chameleon side by side, the spikes along the ridge of the chameleon’s spine are smaller and less prominent than they are in the male. 

As a male Jackson’s Chameleon competes with other males for a mate, it uses its size and intimidating posturing to scare off the competition. 

In the case of a fight between two males where neither male will back down, the male Jackson’s Chameleons will even go so far as to butt heads, which is why they develop their horns.

In these sparring matches, the larger male chameleon will often be the victor. So chameleon size can be a major factor in whether a male chameleon in the wild gets to breed or not. 

Factors That Affect Jackson’s Chameleon Size

When Jackson’s Chameleons are growing, there are three reptile husbandry factors that can affect their final size at full adult growth.

This means that people who care for Jackson’s Chameleons have some influence on how big their chameleon eventually grows. Here’s a breakdown of the three factors that most affect Jackson’s Chameleon size. 

Diet and Jackson’s Chameleon Size

For Jackson’s Chameleons to achieve their optimal size, they need to be provided with plenty of food and some variety in their diet. To help your chameleon grow and thrive, feed the chameleon nutritious food items such as the following:

  • Gut Loaded Live crickets
  • Dubia roaches
  • Gut-Loaded Meal Worms 

Jackson’s Chameleons should be fed gut-loaded insects that are appropriately sized. The insect should be no bigger than the space between their eyes. Proper nutrition is a key factor that can affect Jackson’s Chameleon size.


Along with providing live insects for nutrition, chameleon keepers who own Jackson’s Chameleons should also look into providing them with dietary supplements that can help make up for any lack of variety in their diet. 

Keep in mind that in the wild, a chameleon will have access to dozens of different food sources that can keep them supplied with calcium and other trace minerals.

Without that variety, it’s up to humans to supplement their diet. This can be done by dusting either live insects with a nutritional supplement for chameleons

One of the most important minerals for chameleons is calcium since chameleons kept indoors will not have access to the proper amounts of sunlight for them to produce their own. 

Without proper calcium levels, chameleons can become prone to a husbandry disorder known as metabolic bone disease. This malnutritional disease can lead to lethargy, loss of appetite, broken bones, and even death. 

Lighting and Humidity

Another husbandry element that can affect a Jackson’s Chameleon’s size is the humidity and lighting of its enclosure.

Chameleons need UV exposure to properly metabolize their food, and humidity affects a chameleon’s ability to shed. 

A chameleon shedding its skin is a product of its growth process, so in order to grow bigger, a chameleon needs to be able to successfully shed its skin.

Lack of humidity can prevent the chameleon’s skin from shedding, which interferes with its ability to grow larger. 

A chameleon’s enclosure should typically be kept at 60-80% humidity since this replicates its living conditions in the wild. However, it’s important not to increase humidity in the enclosure once a chameleon has begun to shed.

Too much humidity can cause the old skin to stick and make the shed last longer. 

Jackson’s Chameleon Enclosure Size

The bare minimum size enclosure for a Jackson’s chameleon is at least a foot and a half deep, a foot and a half wide, and three feet tall.

But chameleons should ideally be allowed more enclosure space as possible. Many chameleon owners report fewer husbandry issues in enclosures that are at least two feet wide and two feet deep. 

Here are a few other tips to keep in mind when it comes to picking out the proper size for your Jackson’s Chameleon enclosure: 

  • Provide vertical height. Jackson’s Chameleons are arboreal (tree-dwelling) animals, which means they appreciate having plenty of branches and other objects in the cage that allow them to climb up off the cage floor.
  • Don’t forget about the ventilation. Even though Jackson’s Chameleons need a high level of humidity, they also need lots of clean, circulating air. Choosing an oversized enclosure can improve ventilation, and so can using the right enclosure materials. 

Make sure that Jackson’s Chameleons have plenty of space to climb and enjoy themselves. This can go a long way toward making them happy in captivity.

Happy chameleons with plenty of environmental enrichment often live longer and more active lives.

For more on sizing for a Jackson’s Chameleon enclosure check out my article: Proper enclosure size for a Jackson’s Chameleon

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