Newfoundland Weight, Size & Lifespan
How big does a Newfoundland get?
A full-grown Newfoundland is a giant dog, weighing about 100–150 lb as an adult.
- Adult weight
- 100–150 lb
- Also in kilograms
- 45.4–68 kg
- Size class
- Giant
- Life expectancy
- 9–10 years
Newfoundland Size
As a giant breed, a Newfoundland keeps growing for longer than a small dog — larger breeds reach their adult weight months later (Hawthorne et al., 2004). Expect steady growth well past the first year.
Newfoundland Lifespan
How long do Newfoundlands live?
The American Kennel Club publishes a life expectancy of 9–10 years for the Newfoundland, on its breed page. That is a figure for the breed, not a prediction for one dog — an individual Newfoundland can fall on either side of it.
A second source measured it instead of publishing it. McMillan et al. (2024) followed 1,529 dogs of this breed in the United Kingdom and recorded 633 deaths, giving a median age at death of 11 years (95% CI 10.9–11.6 years).
⚠️ The two do not agree, and the gap is not small: 9–10 years against 11 years. We show both rather than averaging them, because they are not measuring the same thing. The AKC figure is what the breed club publishes for the breed; the McMillan figure is the age half of the dogs in that study had died by. A median at death sits below a life expectancy almost by construction — and here it lands above the published range, which is worth knowing either way.
Newfoundland Growth Chart
What a Newfoundland puppy weighs week by week, from the growth curve FEDIAF publishes (Nutritional Guidelines 2025, Table VII-8a) for a dog whose expected adult weight is 56.7 kg. It is an average, not a target, and it is only valid from 8 weeks to one year — FEDIAF notes that growth patterns show a certain individual variability. Read a row as the middle of a spread.
| Age | Weight | % of adult weight |
|---|---|---|
| 8 weeks | 17 lb (7.8 kg) | 14% |
| 10 weeks | 27 lb (12.4 kg) | 22% |
| 12 weeks | 36 lb (16.2 kg) | 29% |
| 14 weeks | 43 lb (19.4 kg) | 34% |
| 16 weeks | 49 lb (22.2 kg) | 39% |
| 18 weeks | 54 lb (24.6 kg) | 43% |
| 20 weeks | 59 lb (26.8 kg) | 47% |
| 24 weeks | 67 lb (30.6 kg) | 54% |
| 28 weeks | 75 lb (33.8 kg) | 60% |
| 32 weeks | 81 lb (36.6 kg) | 64% |
| 36 weeks | 86 lb (39.0 kg) | 69% |
| 40 weeks | 91 lb (41.2 kg) | 73% |
| 44 weeks | 95 lb (43.2 kg) | 76% |
| 48 weeks | 99 lb (45.0 kg) | 79% |
| 52 weeks | 103 lb (46.6 kg) | 82% |
Common questions
How much does a full-grown Newfoundland weigh?
A Newfoundland weighs 100–150 lb (45.4–68 kg) as an adult. That range is the weight the American Kennel Club publishes in the breed's official standard, re-checked here every week — it is a typical weight across many adult dogs, not a target for one dog.
Is a Newfoundland a giant dog?
Yes — a Newfoundland counts as a giant breed, going by the middle of its adult weight range (45.4–68 kg). The cut-offs between small, medium, large and giant are a common veterinary convention rather than one official standard, so a breed near a boundary can be described either way elsewhere.
When does a Newfoundland stop growing?
Later than a small dog. Hawthorne et al. (2004) measured that larger breeds keep gaining weight for longer, so a Newfoundland is likely to fill out well past its first birthday. We don't publish a month-by-month figure, because no source gives one breed by breed — and an invented number would be worse than none.
Why is there a range instead of one weight?
Because the source publishes a range. Within any breed, weight varies with sex, genetics, build and health, and a mixed-breed dog usually falls between its parents' breeds. Narrowing 100–150 lb down to a single number would look more precise while being less true.
How long do Newfoundlands live?
The American Kennel Club publishes a life expectancy of 9–10 years for the breed, re-checked here every week. That is a figure for the breed, not a prediction for one dog: an individual Newfoundland can fall on either side of it, and how a dog is fed, exercised and cared for moves the odds. A second source measured it rather than publishing it: McMillan et al. (2024) followed 1,529 dogs of this breed in the United Kingdom, recorded 633 deaths, and report a median age at death of 11 years (95% CI 10.9–11.6 years). The two disagree here — 9–10 years against 11 years — and we show both rather than averaging them, because they are not measuring the same thing.
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Weight varies within the Newfoundland by sex, genetics and health, and mixed-breed dogs fall between their parents. This is a typical range, not a guarantee.
Verified on . Based on Breed weights — official AKC breed standards (American Kennel Club, breed pages, accessed 2026-07-29), Breed life expectancy — AKC breed pages (American Kennel Club, breed pages, accessed 2026-08-10), Longevity of companion dog breeds: those at risk from early death — Supplementary Table S3 (McMillan et al., Scientific Reports (2024), 14:531, 584,734 UK dogs — Kaplan-Meier median survival for 155 breeds), Body-Weight Changes during Growth in Puppies of Different Breeds (Hawthorne et al., Journal of Nutrition, 2004, vol. 134, p. 2027S) and Nutritional Guidelines for Complete and Complementary Pet Food for Cats and Dogs (FEDIAF (European Pet Food Industry Federation), 2025 edition (growth curves Table VII-8a, growth energy VII-8b and VII-10)). See the method.