The Beaver’s Size and Weight (Your Questions Answered)

If you’ve ever seen a beaver, you might think that these creatures are only 50 pounds or so. Although the average weight is 55 pounds, many beavers are a lot bigger.

In fact, the average weight for a beaver is 55 pounds, with the largest being 110 pounds. This large size is explained by the fact that beavers never stop growing. Needless to say, beavers are a lot bigger than most people expect them to be.

Knowing the averages is not enough to fully understand the size, weight, and shape of beavers. Keep reading to fully understand the size and weight of these unique mammals.

How Big Are Beavers?

From a distance, beavers may look about the same size as a big cat, but they’re actually much bigger. Most beavers reach up to 70 pounds in weight, but there are several that weigh as much as 100 pounds. As a result, a beaver’s weight is most comparable to a dog’s weight.

As for the length, most beavers can grow to be 40 inches long, including the tail. For more perspective, that is about 3.333 feet long. Though they are very long, most only grow to be 1 or 1.5 feet tall. this short stature s why most are shocked to learn about their weight.

The size and weight don’t always seem comparable. After all, most creatures that are only 1.5 feet tall and 3 feet long are rarely close to 100 pounds.

The beaver is an exception, and with good reason. Their coats are incredibly thick, and their tails are covered in thick leather. Plus, they have powerful teeth and jaws so that they can chew through wood.

Not to mention, beavers are continuously growing, up until the day they die. The beaver’s teeth continue growing as well. Most upper incisors grow to be 20 to 25 mm. Put all of this together, and a beaver’s weight is much heavier than its size suggests.

How Big Is A Full Grown Beaver?

A full-grown beaver typically grows to be 25 to 39 inches long.

The healthy weight varies quite a bit. Most healthy beavers weigh between 24 and 71 pounds, with 55 pounds being the average weight. However, beavers can grow to be much bigger, with the largest being 110 pounds in total.

Although these are the average sizes, keep in mind that adult beavers never stop growing. So, there will never be a time that a beaver reaches its total adult size until it dies. This explains why they are the biggest rodent in the US. 

How Much Does A Beaver Weigh?

On average, beavers weigh a total of 55 pounds, but the age of the beaver will largely impact its weight. Some adult beavers can weigh as little as 24 pounds, and the heaviest on record is 110 pounds. This is a huge range in healthy beaver weight.

Once again, since beavers never stop growing, the weight will continue to pack on until the beaver passes away. Until then, more and more pounds will be added to the beaver’s cute body.

What’s The Biggest Beaver On Record?

The largest beaver on record was from Iron County Wisconsin. This North American beaver was 110 pounds, making it insanely large, even when compared to other large beavers.

Are Male Beavers Bigger Than Females?

Beavers are one of the few animals where the males and females grow to be the same size. In fact, there are many cases of female beavers being bigger than males. This is incredibly uncommon among mammals. Still, males and females are about the same size.

How Big Is A Baby Beaver?

When beavers are born, they are called kits. Typically, there are two to four kits for every litter. Kits are born with the ability to swim, though they don’t do much swimming for the first few weeks of their lives because of their small size.

Most kits are born weighing about 1 pound or 7 inches in length. As you might imagine, they make easy prey for most predators due to this itty bitty size. How quickly kits are weaned from their mother depends on the type of beaver in question.

American kits get weaned after two weeks, whereas Eurasian kits take six weeks or more. In comparison, Eurasian kits are 8.1 to 21 oz, and American kits are 9 to 21 ounces.

After the weaning process is over, the kits aren’t quite ready to leave home yet. Most will leave home once they are about 2 years old and will start mating whenever they are 3. Unlike many other species, beavers mate during the winter months.

The gestation period of beavers differs based on the species as well. Eurasian beavers take 2 to 4 months, whereas American beavers take 3.5 months. Once the pregnant mother gives birth, the process starts all over again with her kits.

At What Age Are Baby Beavers Fully Grown?

Baby beavers are not typically fully mature until they are at least 2 to 3 years old. Maturity is mainly determined by sexual maturity. Most beavers don’t reach sexual maturity until they are at least 3 years old, but sex impacts age.

For females, this is almost always when they are 2.5 years old, but there’s a bit more wiggle room with males.

Once beavers reach maturity, they can live a decade or longer. On average, beavers live a total of 16 years, meaning beavers have a long life ahead of them after reaching sexual maturity.

Giant beavers Once Lived In America

Believe it or not, giant beavers once lived in America. During the Ice Age, there was a species widely known as Castoroides. This species has a lot of strikingly similar characteristics to the beaver, but it had some distinct differences too.

Most notably, these creatures are believed to have been 8 feet long and nearly 200 pounds. More so, the prehistoric beavers did not have the tail we know of today.

Still, these giant beavers are similar to modern beavers in a number of ways. They were even semi-aquatic much like the adorable beavers we see today.