How Big Do Australian Shepherds Get?

Full-grown Australian Shepherds are usually considered medium-sized dogs.

According to the AKC, these are the expected measurements for adult Aussies:

Of course, you can never guarantee what size your puppy will reach as an adult. The breed standard, which good Australian Shepherd breeders aim for, is just the size full-grown Aussies are supposed to be — your dog could end up anywhere within that range, or even outside it.

In particular, there’s a good amount of variation in terms of weight. According to Brittany Greendeer, the breeder behind Riot Australian Shepherds in Plover, WI, that owes in part to the fact that individual Aussies are just built differently.

“There are some dogs with thick, chunky legs,” she says, “and some dogs with really spindly legs.”

When do Australian Shepherds stop growing?

Australian Shepherds usually reach their adult height at about a year old, but they fill out during their second year, says Jill Porter, the breeder behind Faithwalk Aussies in Hillsdale, MI. In Greendeer’s experience, they can continue to mature physically until they're 3 or 4 years old.

Chris Vandall and Keith Ambuhl’s 3-year-old Aussie, Archer, got to his current weight of 55 pounds when he was about 2 years old — right on the lower end of the 55-65 pounds the breeder thought he’d be.

“A week after we got him, we took him on a plane in a little pet carrier and he was just perfect,” says Ambuhl. “We love the size dog he is now, but it would be great to take him on a plane any time we want.”

One more factor to keep in mind in terms of Australian Shepherd size is diet and exercise. Aussies are not particularly prone to obesity — “They are extremely active and very easy to keep fit,” says Sara Koenig, the breeder behind Nicara Kennel in Mazomanie, WI — but just like any other dog, you have to make sure to take proper care of them. Just ask Regan Abromitis.

“My first Aussie gained 15 lbs when I left him home for a semester in college,” she says. “My parents are terrible with dogs.”

What’s it like to live with a full-grown Australian Shepherd?

Hannah Weiger has three Aussies herself, and she also happens to live with an Aussie breeder, putting her household’s current dog count at 8. So take her word for it when she says that Australian Shepherds are “not huge, but not itty-bitty.” Depending on the size of the dog and the person, you may or may not be able to pick up your pup with ease.

How does an Aussie literally fit into your life?

Breeder Jill Porter says they take up at least one couch cushion when they’re curled up sleeping. Natalie Volpicelli lets her 13-year-old Aussie, Rocky, sleep in her twin-sized bed with her, but sometimes he kicks her off and she has to reclaim her spot. And Mikayla Morris says that her Aussie, Spider, who already weighed 55-60 lbs at just 13 months, takes up the majority of the back seat in her Toyota Corolla.

Spider is big enough, Morris says, that if he were to run at you full force, he could knock you over. But, she adds, “he does think he’s a lapdog.”