When is a Cavalier King Charles Spaniel fully grown?

Most Cavaliers reach their adult size by 10–12 months of age. Small breeds mature faster than large breeds, so the growth window is shorter. Some dogs may fill out slightly into their second year, but meaningful weight gain after 12 months is more likely overfeeding than continued growth.

How much should a 3-month-old Cavalier weigh?

There is meaningful variation, but a 3-month-old Cavalier puppy might typically weigh in the range of 1.5–3 kg, depending on their eventual adult size and individual development. Consistent upward progress on the scale each week matters more than any single target number.

My Cavalier puppy seems very small for their age — should I be worried?

Not necessarily — litter variation is normal, and some Cavaliers are simply smaller than average. However, if your puppy's weight is dropping or completely flat over two or more consecutive weeks, or if they seem lethargic or not eating well, a vet visit is appropriate.

Cavalier King Charles Spaniel Growth Chart: What to Expect | PetCalculator

Cavaliers are a small breed that typically reaches adult size by 10–12 months. This guide walks through growth milestones, appropriate weight gain by stage, and how to tell if your Cavalier puppy is growing normally.