How Big Do British Shorthair Cats Get?
British Shorthairs are chunky. Not just “chubby after a big meal” kind of chunky—more like teddy bear levels of thick. But don’t worry, it’s not all fat. They’re just built that way.
Let’s break down how big they actually get and what to expect if you’re planning to bring one home.
Average Size of a British Shorthair
These cats take their sweet time growing. While most cats reach full size by a year, British Shorthairs laugh in your face and keep growing until they’re 3 to 5 years old.
Here’s what you’re looking at once they’re fully grown:
| Category | Male British Shorthair | Female British Shorthair |
|---|---|---|
| Weight | 12 to 17 lbs (5.5–7.7 kg) | 8 to 13 lbs (3.6–5.9 kg) |
| Length (nose to tail) | 22 to 25 inches (55–63 cm) | 20 to 22 inches (50–56 cm) |
| Height (shoulders) | 12 to 14 inches (30–36 cm) | 11 to 13 inches (28–33 cm) |
So yes, they’re big. Not Maine Coon big—but still very solid.
By the way, if you're into British Shorthair stuff, you’ll wanna check this one out: Are British Shorthair Cats Friendly? Let’s Clear the Air
Why Are They So Bulky?
They were bred that way. British Shorthairs were originally working cats—mousers, barn guards, royal fluffballs—you name it. Their body is dense, with strong muscles and a broad chest.
Also, that round face and plush fur just add to the overall thick-cat illusion.
Oh, and speaking of British Shorthair, here’s another one you might like: How Long Do British Shorthair Cats Live?
Male vs Female Size
The boys are noticeably bigger. If you want a true tank of a cat, a male British Shorthair is your pick. But even the females are still heavier than your average house cat.
And again, don’t judge their adult size too soon. They start off like little plush potatoes and then slowly build mass over the years.
Also, just throwing this in—this British Shorthair post is a fun read too: Do British Shorthair Cats Shed?
When Do They Reach Full Size?
You’re in for a long ride.
- By 1 year: They’ll look like adult cats, but they’re still growing.
- By 2 years: Starting to fill out more.
- By 3 to 5 years: That’s when they finally stop growing.
If your British Shorthair is 2 and still looks a little lean, give it time. The final form takes patience.
Signs Your Cat Is Growing Normally
Keep an eye on these:
- Their weight is going up steadily but not rapidly.
- Their legs are strong and not wobbly.
- Their appetite is healthy—not obsessive.
- Their coat is getting denser, which is normal as they age.
If they balloon in size overnight, that’s not “growth”—that’s a vet visit.
Do They Need Special Diets to Grow Big?
Nope. Just good quality food and portion control. British Shorthairs are prone to weight gain, so don’t overfeed just to “bulk them up.”
Stick to:
- Protein-rich wet food or high-quality kibble
- Treats in moderation
- Regular play to keep them active
Their size comes from genetics, not extra servings of tuna.
Final Thought
British Shorthairs are built like plush tanks. They grow slow, they grow big, and they grow cuddly. Just don’t confuse “big” with “overweight,” and you’ll have one healthy, round-faced roommate.
Got one already? Then you know—once they flop on your lap, you’re not going anywhere for a while.
