Use this Border Collie puppy weight calculator to predict how big your puppy will get. Border Collies are a herding breed that typically reaches full size by around 12-15 months.
Enter your puppy's current weight and age to predict their adult size
Estimates based on breed growth curves. Individual dogs vary with genetics and nutrition — check with your vet for a personalized read.
A practical pick for medium-sized breeds.
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| Age | Weight |
|---|---|
| Birth | 1 to 2 lbs |
| 2 Months | 5 to 11 lbs |
| 3 Months | 8 to 17 lbs |
| 4 Months | 11 to 22 lbs |
| 5 Months | 14 to 28 lbs |
| 6 Months | 17 to 33 lbs |
| 7 Months | 20 to 39 lbs |
| 9 Months | 23 to 44 lbs |
| 10 Months | 26 to 50 lbs |
| 1 Year | 29 to 54 lbs |
| 1.5 Years | 30 to 55 lbs |
| 2 Years | 30 to 55 lbs |
Estimated from typical medium-breed growth curves and the Border Collie's adult weight range. Individual puppies vary — use the calculator above for a prediction based on your puppy's actual current weight.
New breed data, growth tips, and puppy-parenting insights, plus our free printable puppy growth tracker.
Border Collies are prone to hip and elbow dysplasia, epilepsy, and Collie Eye Anomaly, an inherited condition that can cause blindness and is usually detected by 5-6 weeks of age via ophthalmologic exam. Some Border Collies also carry the MDR1 gene mutation that causes drug sensitivity, so it's worth testing before any new medication.
Match food to the breed's genuinely high activity level — Border Collies working or exercising heavily need more calories than a sedentary dog of the same size, and portions should scale with actual daily activity.
The double coat (smooth or rough) sheds moderately; brushing once or twice a week keeps it manageable.
This is a breed that needs a real job — herding, agility, obedience, or serious daily mental work. Without it, that famous intelligence turns into anxiety, obsessive behaviors, or destructiveness. Not a breed for a low-activity household.
The Border Collie was developed along the England-Scotland border region to herd sheep, selected purely for working ability rather than appearance — the breed was standardized by 1906 based on function, and the AKC didn't recognize it until 1995, partly because working breeders resisted a standard that might prioritize looks over herding skill.
Widely regarded as the most intelligent dog breed, Border Collies were bred to use an intense, focused gaze ("the eye") to control livestock movement — that same intensity and drive needs a serious outlet in a companion home, or it turns into obsessive or anxious behavior.
