Kangaroo Size: How Big They Get & What Makes Them Grow

Kangaroos grow to anywhere between 2 ft 7.5 in and 5 ft 10 in tall and weigh between 28.6 to 145 pounds. Red kangaroos are the largest and eastern gray kangaroos are the heaviest species. Exercise, genes, and nourishment determine their growth.

Kangaroos are often pictured as cute and fluffy animals by nature lovers. They live in most people’s minds as joyful little creatures hopping around in Australia.

You might be surprised to learn that Kangaroos can get huge. But how big do they get exactly and what makes them grow?

This article covers everything you need to know about kangaroos’ height, weight, and the factors that determine their growth.

How Tall Are Kangaroos?

Full-grown kangaroos are between 2 ft 7.5 in and 5 ft 10 in tall. Different kangaroo species have different sizes. Red kangaroos are the biggest species and the smallest are the black wallaroos.

Kangaroos are the biggest mammals in their homeland, Australia. Their height ranges between 2 ft 7.5 in^[1] and 5 ft 10 in.^[2]

Kangaroos’ height differs from species to species.^[3] Here are the six kangaroo species from largest to smallest:

1. Red kangaroo
2. Eastern gray kangaroo
3. Western gray kangaroo^[4]
4. Antilopine kangaroo^[5]
5. Common wallaroo^[6]
6. Black wallaroo^[7]

You can read about different kangaroo species’ sizes in more detail later in the article.

Average Kangaroo Height

Kangaroos are 31 to 71 in tall, on average. Their height is determined by their species, age, and gender. Kangaroo males are taller than kangaroo females.

The height of kangaroos greatly varies on three factors:

1. Species
2. Age
3. Gender

Regardless of species, kangaroo males tend to grow much bigger than females. Age also plays a huge part. Kangaroo joeys are born about one inch long and grow to their full size when they reach adulthood.^[8]

Kangaroo	Height
Adult male	3 ft 3.4 in—5 ft 10 in
Adult female	2 ft 7.5 in—3 ft 7 in
Baby	1 inch at birth

Male Kangaroo Average Height

Kangaroo males are much taller than females on average. The smallest males (black wallaroos) are around 3 ft and 3.4 in and the biggest ones are red kangaroo males at that measure.

Female Kangaroo Average Height

Kangaroo females’ are much shorter than males. They evolved to be shorter as they do not brawl with each other and aren’t tasked with defending the mob. Black wallaroo females are about 2 ft 7.5 in tall and red kangaroo does are 3 ft 7 in tall.^[9]

Baby Kangaroo Height

Baby kangaroos are born about one inch long. They are hairless, blind, and severely underdeveloped at birth. The babies need to crawl inside their mother’s pouch to develop.

In about 15 to 24 months, joeys grow to their full size which can be 72 times bigger than their length at birth.

How Big Do Kangaroos Get in Captivity?

Captive kangaroos generally grow to their full size. They need special care to develop correctly. Kangaroos need large living space and proper food to reach their full size.

Kangaroos are persevering animals. They are used to the harsh weather conditions of their native Australia and evolved to be tough. Regardless, they still need proper space and food to grow.

How Much Space Do Captive Kangaroos Need to Grow?

Kangaroos in captivity need about 50 ft² to move around and brawl. They are active animals that cover vast distances in the wild. Kangaroos need a lot of space for muscle development.

What Food Do Captive Kangaroos Need to Grow?

Kangaroos are herbivores and survive on plants in the wild.

Captors should provide them with vegetation they would find in their natural habitat:

• Bushes
• Grass
• Leaves
• Shrubs
• Flowers
• Fruits
• Vegetables

Kangaroos’ food intake depends on their development and weight. A 55 pounds red kangaroo female eats about one pound and a 132 pounds male eats two pounds of dry matter per day.^[10]

One-year-old joeys need about 95% of an adult female’s daily energy intake.

Average Kangaroo Weight

Kangaroos weigh between 37.5 and 145 pounds. The heaviest species are the eastern gray kangaroos and the lightest are the black wallaroos. Males are much heavier than females.

Kangaroos’ weight depends on their species. Although red kangaroos are the largest, the eastern gray kangaroos are the heaviest on average.

Here are the six kangaroo species from heaviest to lightest:

1. Eastern gray kangaroo
2. Red kangaroo
3. Western gray kangaroo
4. Antilopine kangaroo
5. Common Wallaroo
6. Black Wallaroo

Kangaroo	Weight
Adult male	48.5—145 pounds
Adult female	28.6—75 pounds
Baby	0.03 ounces at birth

Kangaroo Male Average  Weight

The average weight of kangaroo males is anywhere between 48.5 to 145 pounds. Although the eastern gray kangaroos are the heaviest on average, the individuals weighing the most are usually red kangaroos. They can reach a body mass of 200 pounds.

Male kangaroos are muscular. Their society is hierarchical and males often fight to assert dominance. The alpha male is the largest and strongest of the mob and the strongest around.

Kangaroo Female Average  Weight

Kangaroos females weigh less than males. They are usually about half the weight of their male counterparts.

Female kangaroos don’t need to be muscular as their role is to nurture and care for their young. They usually don’t get into fights.

Baby Kangaroo Average Weight

Baby kangaroos are underdeveloped at birth and weigh only about 0.03 ounces. They grow rapidly throughout their childhood. A red kangaroo joey can gain as much as 0.5 pounds between 20 and 100 days old.^[11]

Kangaroo Growth Chart

Kangaroos grow at a breakneck speed in their childhood. They are born weighing 0.03 ounces, but they can be a thousand times as heavy by one year old. Kangaroos are fully grown when they reach adulthood at sexual maturity (males: 24-40 months, females: 15-30 months).

The growth of kangaroo joeys is unprecedented in the animal kingdom. From when they are born until adulthood they can grow thousands of times their original size.^[12]

Kangaroos have four life stages:

1. Newborn
2. Young of the year
3. Juvenile
4. Adult

Life stage	Height	Weight
Newborn	Around 1 in	0.03 ounces
Young of the year	1 it to around 3 ft	4.4—22 pounds
Juvenile	Around 3 ft—adult height	22—40 pounds
Adult	2 ft 7.5 in to 5 ft 10 in	28.5—145 pounds

When Are Kangaroos Fully Grown?

Kangaroos reach their full height when they reach adulthood. Kangaroo males can build a considerable amount of muscle during their childhood and when they are adults.

Kangaroos become adults when they reach sexual maturity. Males reach maturity later than females on average.

Kangaroo Gender	Age at Sexual Maturity
Male	24—39 months
Female	15—30 months

Factors that Influence Kangaroo Growth

Kangaroos’ growth is inconsistent. An individual living in more arid regions with poor quality vegetation may not reach its full potential size. Kangaroos also need daily movement for muscle development.

Here are the main factors that influence kangaroos’ growth:

• Species
• Gender
• Nutrient intake
• Water availability
• Genes
• Exercise quality and quantity

Kangaroo Species Size Comparison

Each kangaroo species have different heights and weights. Males are generally taller and heavier than females.

Eastern gray kangaroo males are the heaviest, and red kangaroo males are the largest.

Species	Average Adult Male Height	Average Adult Female Height	Average Adult Male Weight	Average Adult Female Weight
Red kangaroo	4.9 ft	3.6 ft	110 pounds	50 pounds
Eastern gray kangaroo	4.3 ft	3.3 ft	120 pounds	80 pounds
Western gray kangaroo	4.3 ft	3.3 ft	100 pounds	62 pounds
Antilopine kangaroo	3.9 ft	2.6 ft	90 pounds	44 pounds
Common wallaroo	3.5 ft	2.5 ft	70 pounds	40 pounds
Black wallaroo	3.2 ft	2.5 ft	45 pounds	29 pounds

Conclusion

Kangaroos are the largest mammals of Australia. They can be as tall as 5 ft 10 in and as heavy as 145 pounds on average. Red kangaroos are the largest and eastern gray kangaroos are the heaviest kangaroo species.

Kangaroos grow rapidly after they are born. They can be thousands of times as big as their at-birth size. Kangaroos’ growth is determined by gender, species, nutrient intake, and exercise.