Mastiff Age in Human Years: Free Calculator
Work out your Mastiff age in human years. Mastiffs typically weigh 120–230 lb and live 6–10 years; enter your dog's age below.
One of the heaviest breeds. Size class: Giant (over 100 lb (45 kg)). Senior from about 6 years.
Mastiff key numbers
| Typical adult weight | 120–230 lb (54.4–104.3 kg) |
| Typical lifespan | 6–10 years |
| Fully grown (adult) from about | 2 years |
| Senior from about | 6 years (≈49 human years) |
| Human age at 10 years | ≈79 |
| Daily calories, neutered adult | 2244–3656 kcal |
Mastiff age in human years: year-by-year chart
| Dog age | Size-based chart | UCSD formula | Life stage |
|---|---|---|---|
| 1 | 12 | 31 | Puppy |
| 2 | 22 | 42 | Adult |
| 3 | 31 | 49 | Adult |
| 4 | 38 | 53 | Adult |
| 5 | 45 | 57 | Adult |
| 6 | 49 | 60 | Senior |
| 7 | 56 | 62 | Senior |
| 8 | 64 | 64 | Senior |
| 9 | 71 | 66 | Senior |
| 10 | 79 | 68 | Senior |
| 11 | 86 | 69 | Senior |
Feeding a Mastiff
At a typical adult weight of 175 lb (79 kg), a neutered adult needs roughly 2978 kcal a day. Use the dog food calculator for your dog's own weight and food.
Frequently asked questions
How old is a Mastiff in human years?
A Mastiff's age in human years depends on size. A Mastiff is a giant breed (120–230 lb), so on the size-based chart it is about 45 human years at 5 and 79 at 10. A typical Mastiff lifespan of 6–10 years is about 64 human years at the midpoint.
How long do Mastiffs live?
Typically 6 to 10 years. One of the heaviest breeds.
When is a Mastiff a senior?
From around 6 years old, which is the last quarter of a typical lifespan. Ask your vet about senior check-ups before then.
Other giant breeds
See all breeds · General dog age calculator