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Iguana Size & Weight Chart – How Big do Iguanas Grow?

Iguanas make one of the most popular pets for all types of keepers. Regardless of whether you are a beginner or advanced pet lizard hobbyist, you will find these pets to be quite fascinating.

One of the things that will fascinate you the most is how big they can grow. Therefore, you will have to find out about their overall sizes to help decide whether a particular species is right for you and your home in particular.

Their sizes will help you decide on how big their cages should be especially when they are already mature. Below is a simple guide to iguana size and growth chart.

Iguana Size & Weight Chart

Just like most pets, iguanas take a few years to grow to their full size. On average they can reach their full sizes at four years. Some will keep on growing until they are seven or eight years old.

Also, iguanas grow at different rates and speeds. Initially, they start to grow a little fast but slow down considerably after three to five years of their age.

In some cases, iguanas can stop growing for a couple of months before they resume again. Therefore, it is wise to keep a chart showing their growth progress. Your iguana growth chart should look like the one below:

Green Iguana Size and Weight Chart

Age Snout to Vent – Body Lenght Snout to Tail Tip – Body Lenght Weight
Just hatched 2 in 6 – 8 in 0.2 lbs
3 months old 4 in 12 in 0.3 – 0.5 lbs
6 months old 6 in 18 in 0.6 – 1 lbs
1 year old 8 in 24 in 1 – 1.5 lbs
18 months old 10 in 30 in 1.6 – 2 lbs
2 years old 12 in 36 in 2 – 4 lbs
3 years old 16 in 45 in 4 – 6 lbs
4 years old 18 in 54 in 5 – 8 lbs
5 years old 20 in 60 in 10 – 15 lbs
6 years old 22 in 66 in 14 – 18 lbs
7 years old 24 in 72 in 15 – 20 lbs

Iguana tail length may range from 2.5 to 3 x the Snout to Vent length.

The age/size chart above will help you have an idea of how you can determine your pet iguanas’ size, and weight at different stages of their growth. The chart is definite since it does not include all iguana species that can be kept as pets.

How Fast do Iguanas Grow?

Iguanas are known to grow at a fast rate at the beginning of their lives. This means that they grow incredibly fast during their early years. You will easily notice how quickly these pet lizards grow immediately after they hatch.

For example, a green iguana grows at an average rate of 2 meters until they reach maturity. As a matter of fact, green iguanas are part of the largest iguana species. Their growth slows down at the age of 4 years when they start to fill out as opposed to increasing body length. At this stage, they increase their weight.

How Big are Baby Iguanas?

Baby iguanas can be as large as 2 inches from head to vent and weigh about 0.2lbs when they are just hatched. At 3 monthds old, baby iguanas can measure 4 inches from head to vent and 12 inches total lenth from snout to tail.

The size of fully-grown iguanas varies from one species to another. However, they are large-sized pet lizards with sturdy build that resemble dragons. The average mature iguana can grow to a body length of about 5 to 7 feet and weigh 13.2 to 17.6 pounds.

Most keepers prefer their pet reptiles to be larger because they believe that larger pets are healthy.

When do Iguanas Reach Full Size?

Most iguana species can grow to full size at the age of about 7 years as indicated in the above chart. Some can reach their maturity at around 2 to 3 years of age but this depends solely on the species and the environment in which they are growing.

Besides, iguanas will grow at different rates and speeds. In some cases, they may stop growing for a couple of months before starting all over again until they reach their maturity at 7 or 8 years old.

Male or Female Iguanas – Which Ones are Bigger?

Female iguanas are usually smaller than males in all physical attributes. Besides, there are some variations in terms of regional differences in sizes and mass.

The actual size of iguanas is dependent upon their origin. But overall both the masses and sizes of individual iguanas will fall within the above-listed ranges on the chart.

How Much Space Does an Iguana Need?

Since iguanas are large pets, they prefer larger spaces that will enable them to grow without any hindrance. Therefore, the most appropriate way to prevent the stunted growth of your iguanas is to look for a terrarium that is at least 1.5 times the average length of your largest iguana.

The height should also be 1.5 times that of your iguana and at least 1 times the width. Most importantly, you should find a cage that measures 36x48x18 inches to keep your growing iguana.

Wrap Up

Iguanas can grow fairly larger than most lizards although their sizes depend on individual species. On average they can grow to about five feet long or even more than that. That is only if you provide them with necessary basic needs such as food, water, security, and a good shelter.

Speaking of the shelter, iguanas require a sizable enclosure that can make them move around freely and grow to their full sizes.

They will also need to spend a few hours outside in addition to requiring the UB-V lighting that promotes their optimal growth and health. That’s why you need a chart such as the one above to closely monitor your iguana’s growth progress given that it is likely to live up to 30 years under good care.

Iguanas - Updated: July 8, 2021
avatar I’m Noah, chief editor at VIVO Pets and the proud owner of a playful, energetic husky (Max). I’ve been a volunteer at Rex Animal Rescue for over 2 years. I love learning and writing about different animals that can be kept as pets.

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