The maths, with your numbers
No guesswork and no brand chart. This is the same calculation a vet does on paper, so you can check it.
A healthy adult Mastiff weighs 120–230 lb (AKC Breed Weight Chart (combined male/female range; AKC standard gives no weight)). Below are daily amounts for that range, for a typical dry dog food (382 kcal per cup, the middle of the dog foods in our list). For your own food, use the calculator above: it is already set to a Mastiff weight.
| Weight | Couch potato | Spayed or neutered | Very active |
|---|---|---|---|
| 120 lb 54.4 kg | 4 ⅜ cups461 g · 1,683 kcal | 5 ⅞ cups614 g · 2,244 kcal | 7 ⅜ cups768 g · 2,806 kcal |
| 175 lb 79.4 kg | 5 ⅞ cups612 g · 2,234 kcal | 7 ¾ cups815 g · 2,978 kcal | 9 ¾ cups1,019 g · 3,723 kcal |
| 230 lb 104.3 kg | 7 ⅛ cups751 g · 2,742 kcal | 9 ⅝ cups1,001 g · 3,656 kcal | 12 cups1,251 g · 4,570 kcal |
Daily totals with no treats. Worked out from resting energy (70 × kg0.75) and the AAHA 2021 life-stage factors. Weight source note: AKC standard gives minimum heights only; weight from AKC Breed Weight Chart.
Good to know
The AKC sums up the Mastiff in three words: courageous, dignified, good natured. How active yours really is matters more for the bowl than the breed name, so pick the column that fits your own dog.
Mastiff puppies are large-breed puppies. VCA Animal Hospitals advises steady, measured feeding of a large-breed puppy food rather than free feeding, and notes that big breeds can take 18 to 24 months to reach adulthood. Use the puppy calculator until then.