Jack Russell Terrier Size & Weight Chart: How Big Do They Get?
Written for general planning, not medical advice — no one at Argos Paws is a veterinarian. If something is wrong with your dog right now, call your vet or the nearest emergency clinic.
Quick answer: A full-grown Jack Russell Terrier typically weighs 13-18 lb (5.9-8.2 kg) and stands 10-14 in (25-36 cm) tall at the shoulder. Most reach their adult size by around 10-12 months.
Photo: Plank · CC BY 3.0 · via Wikimedia Commons
The Jack Russell Terrier is a small, fearless working terrier bred in England to bolt foxes from their dens. Bright, bold, and tireless, Jacks pack big-dog energy into a small frame.
| Size category | Small |
|---|---|
| Typical adult weight | 13-18 lb (5.9-8.2 kg) |
| Height at the shoulder | 10-14 in (25-36 cm) |
| Full grown by | 10-12 months |
| Life expectancy | 13-15 years |
Jack Russells vary in leg length: shorter-legged types stand about 10-12 in, while the leggier Parson Russell type stands 12-14 in.
Jack Russell Terrier weight chart by age (lb & kg)
Estimated weights for an average Jack Russell Terrier puppy, based on the typical growth curve for a small breed. Males usually track toward the top of each figure, females toward the bottom.
| Age | Weight (lb) | Weight (kg) |
|---|---|---|
| 2 months | ~5 lb | ~2.3 kg |
| 3 months | ~9 lb | ~4.1 kg |
| 4 months | ~11 lb | ~5 kg |
| 5 months | ~13 lb | ~5.9 kg |
| 6 months | ~14 lb | ~6.4 kg |
| 10-12 months (full grown) | 13-18 lb | 5.9-8.2 kg |
When does a Jack Russell Terrier stop growing?
As a small breed, Jack Russell Terriers typically reach adult weight by around 10-12 months. Smaller breeds like the Jack Russell Terrier reach full height and fill out fairly close together, so growth tends to look "done" all at once.
Use the Puppy Weight Predictor below — it's pre-loaded with the Jack Russell Terrier's growth curve, so just enter your puppy's current weight and age.
Predict your Jack Russell Terrier's adult weight
Enter your puppy's current weight and age to get an estimate based on this breed's typical growth curve.
Open the Puppy Weight PredictorHow much does it cost to feed a Jack Russell Terrier?
A typical adult Jack Russell Terrier (16 lb, average activity) needs roughly 484 kcal/day — about 0.3 lb (1.1 cups) of dry kibble per day, which works out to around $17/month at typical kibble prices. Fresh or subscription-style food usually costs more, around $193/month for the same dog. These are population-level estimates — use the calculator below for a number based on your dog's actual weight and food type, or see the Jack Russell Terrier feeding chart for puppy amounts by month.
Estimate Jack Russell Terrier food costs
Pre-filled with this breed's typical adult weight — adjust activity level and food type to get your monthly estimate.
Open the Dog Food Cost CalculatorBrowse dog food sized for a Jack Russell Terrier
Compare dry, wet, and breed-specific formulas — filter by your dog's size and life stage to narrow it down.
Browse dog food on Amazon(affiliate link)How old is my Jack Russell Terrier in human years?
The old "×7" rule doesn't hold up — small breeds like the Jack Russell Terrier age at their own rate, not a generic one. Use the calculator below, pre-set to this breed's size.
Convert your Jack Russell Terrier's age
Pre-filled with this breed's size category for a more accurate human-year estimate than a flat multiplier.
Open the Jack Russell Terrier Age CalculatorCommon health considerations
- Patellar luxation (slipping kneecaps) is common in the breed.
- Primary lens luxation, an inherited eye condition that can cause glaucoma, is DNA-tested for in breeding stock.
- Congenital deafness and Legg-Calvé-Perthes disease (a hip joint disorder) also occur.
This is general breed-level information, not a diagnosis or a prediction for any individual dog. Talk to your vet about health screening and preventive care specific to your dog.
Is pet insurance worth it for a Jack Russell Terrier?
See a typical monthly premium for this breed and whether it would likely pay off against a major vet bill.
Jack Russell Terrier insurance costSimilar breeds
Based on energy level, living-space fit, and care needs, these breeds are closest to the Jack Russell Terrier:
Take our breed match quiz
Answer a few quick questions about your lifestyle and living space to see which breeds — not just the Jack Russell Terrier — actually fit best.
Take the Breed Match QuizFrequently asked questions
How much does a full-grown Jack Russell Terrier weigh?
A full-grown Jack Russell Terrier typically weighs 13-18 lb (5.9-8.2 kg), making it a small breed. Individual dogs vary within that range depending on sex, genetics, and body condition — use the Puppy Weight Predictor above for an estimate based on your specific puppy's current weight and age.
How tall is a full-grown Jack Russell Terrier?
A full-grown Jack Russell Terrier stands 10-14 in (25-36 cm) tall, measured at the shoulder (withers). Jack Russells vary in leg length: shorter-legged types stand about 10-12 in, while the leggier Parson Russell type stands 12-14 in.
When does a Jack Russell Terrier stop growing?
As a small breed, Jack Russell Terriers typically reach adult weight by around 10-12 months. Height typically levels off a bit before this; smaller breeds like this one fill out relatively quickly once they reach height.
Is a Jack Russell Terrier a good first dog?
The Jack Russell Terrier is usually better suited to an owner with some prior dog experience. That doesn't rule out a well-prepared first-time owner, but the breed's needs are less forgiving of a learn-as-you-go approach.
How much exercise does a Jack Russell Terrier need?
A lot. The Jack Russell Terrier needs serious daily exercise — 60-90+ minutes, ideally with a job to do (training, fetch, hiking) rather than just a walk. An under-exercised Jack Russell Terrier is a common source of destructive or restless behavior.
Is a Jack Russell Terrier good with kids?
Can do fine with kids, particularly older or calmer ones, but it's more situational than a clear yes — a lot depends on the individual dog's temperament and how it was raised.
How much grooming does a Jack Russell Terrier need?
About as wash-and-go as it gets. The Jack Russell Terrier needs minimal brushing and rarely requires professional grooming.