Boa Constrictor Size: How Big Do They Get?

The boa constrictor (Boa constrictor) is a very popular species of pet snake. While they are not the largest species of commonly kept snake, they can get rather large.

How big does a boa constrictor get?

On average, an adult boa constrictor will be between 7 and 10 feet long depending on sex and subspecies. Most males rarely get over 8 feet, while there have been reports of females reaching 12 feet in length.

Boa constrictor constrictor

This is the snake you likely think of when you picture a boa constrictor or red-tailed boa. Most localities have red tails, but some may be more brown.

These snakes can get up to 12 feet, but most will stick to between 7 and 10 feet in length. Feed slowly if you donā€™t want a giant. Power feeding will result in a very large snake. (see my care and setup guide for boa constrictors)

Boa constrictor longicauda

This subspecies is also known as the Peruvian long-tailed boa. While it doesnā€™t have the longest tail of the boas, it is one of the smallest.

It tops out at 6 feet, making it a great choice for someone who wants a smaller boa. They are common in the pet trade thanks to a calm personality and a number of available morphs. They are rare in the wild due to human activity.

Boa constrictor sabogae

This boa is called the Pearl Island boa since it can be found on that island and the islands of Toboga, Cha Mar, and Taboguilla off the coast of Panama. They stay under 6 feet and breed well in captivity. They may be extinct in the wild since this subspecies is also the target of fear-based slaughter.

Boa constrictor ortonii

This subspecies is called either the Mancanche boa or Ortonā€™s Boa. They are found in Peru and tolerate cold better than any other subspecies.

They are rare or non-existent in captivity. Females can be over 9 feet on average, with males being smaller.

Boa constrictor occidentalis

The Argentine boa is one of the largest boas commonly found in captivity. While it does come in several morphs and patterns in captive animals, females can grow to over 10 feet. They are in danger of extinction in the wild thanks to agricultural deforestation.

Boa constrictor nebulosa

The common name of this boa is the clouded boa.

They are native to the mountainous island of Dominica in the Lesser Antilles. Animals from the southern half of the island rarely get over 8 feet, while females from the north can grow to over 10 feet. They are rare in captivity due to a reluctance to breed and the fact that babies need either lizards or mice scented with lizard skin to convince them to eat.

Boa constrictor orophias

The St. Lucio boa can grow to be over 10 feet. There have been reports of this subspecies reaching 12 feet in length. They are very rare in captivity since they do not breed well in captivity. In the wild, they are regularly killed because of fear.Ā 

Boa constrictor amarali

This snake is known as the Bolivian silver back or short-tailed boa. They can be found in southeastern Bolivia and southern Brazil. T

he Bolivian localities tend to be between 6 and 7 feet long. Brazilian populations tend to be slightly smaller at 5.5-6 feet long. They have the shortest tail of the boas and they are also endangered due to habitat destruction.

Boa imperator

The common boa or Central American boa was once classified as a subspecies ofĀ Boa constrictor. This is because it was once considered that there was only one species in theĀ BoaĀ genus.

A genetic study determined that there were three species in the genus. Many of this species are still sold as being boa constrictors, so be sure to do your research. This species gets up to 5-7 feet and has a docile personality. Some localities of the species have a dwarf gene that means they stay between 3 and 5 feet long.

Boa sigma

The Sonoran boa was the other species that was once considered a subspecies. They are native to the Pacific Coast of Mexico. They tend to stay under 6 feet, but it can be hard to find information since they are the most recently recognized species.


boa constrictor constrictor

The weight of you boa will heavily depend on the subspecies and its body shape. Some subspecies are slender and stay around 10 pounds. Some are heavy-bodied and can weigh over 30 pounds for a large female.

While it is good to watch a petā€™s weight, make sure you look at body condition if you cannot find a growth chart for your boa. You should see good muscle tone, no visible ribs or spine, and no rolls or obvious fat deposits.

If your snake seems round, it is overweight and you should get your snake more exercise and feed either smaller meals or less frequently. Snakes can suffer from obesity and become very sick very fast.


Boa constrictors come in a wide array of sizes and weights. If you want to keep one as a pet, be sure to do your research so you know how large your pet baby boa may get. If you have any questions or comments, please leave them below.

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