Feeding by breed and weight / Working group
How much to feed a Mastiff
A neutered adult Mastiff at 190 lb needs about 3168 kcal a day, which is 8½ cups of a 369 kcal/cup food; at the 180 lb end of the breed's range it is 3042 kcal, or 8¼ cups. That is the maintenance figure before treats, from the resting energy requirement formula and the Merck Veterinary Manual's factor of 1.6 for a neutered adult.
Mastiff feeding table by weight and life stage
Each row is a Mastiff at that weight. Columns are the Merck factors: a neutered adult (×1.6), an intact adult (×1.8) and a dog that is inactive or gains weight easily (×1.4). Cups assume 369 kcal per cup, the label figure for Purina Pro Plan Complete Essentials Shredded Blend Chicken & Rice (adult dry); change it to your bag's number on the sizer.
| Weight | RER | Neutered adult | Cups | Intact adult | Cups | Inactive / weight-prone | Cups |
|---|---|---|---|---|---|---|---|
| 180 lb (81.6 kg) | 1901 | 3042 kcal | 8¼ | 3422 kcal | 9¼ | 2662 kcal | 7¼ |
| 183 lb (83.0 kg) | 1925 | 3080 kcal | 8¼ | 3465 kcal | 9½ | 2695 kcal | 7¼ |
| 185 lb (83.9 kg) | 1941 | 3105 kcal | 8½ | 3493 kcal | 9½ | 2717 kcal | 7¼ |
| 188 lb (85.3 kg) | 1964 | 3143 kcal | 8½ | 3536 kcal | 9½ | 2750 kcal | 7½ |
| 190 lb (86.2 kg) | 1980 | 3168 kcal | 8½ | 3564 kcal | 9¾ | 2772 kcal | 7½ |
RER = 70 × kg0.75; factors from the Merck Veterinary Manual. Calorie density from the Purina product page (3790 kcal/kg, 369 kcal per 8 oz cup, about 96 g). Checked 2026-10-20.
Why the number is lower than the bag says
Bag feeding guides are written for an active, intact adult and often run above the neutered-maintenance figure; for a 190 lb Mastiff the gap between the intact and neutered columns is 396 kcal a day, roughly 1.1 cups. A dog that is already carrying extra weight should start from the inactive column (2772 kcal at 190 lb) and be weighed every two weeks. Treats and chews count: a single dental chew can be 70–100 kcal, which adds up faster than it looks across a week.
Formulas get a healthy adult into the right range; body condition keeps it there. Ribs should be easy to feel under a thin layer of fat, and the dog should have a visible waist from above. If that is not the case after four weeks, adjust by about 10% and re-check — and ask your vet before changing a dog with a medical condition, a pregnant or nursing female, or a working dog in season.
Grams and meals
At 190 lb and 3168 kcal, 8½ cups is about 816 g a day of a 96 g/cup kibble — a kitchen scale is more repeatable than a scoop. Split into two meals for an adult; for a deep-chested breed of this size, two or three smaller meals rather than one large one is the usual advice to reduce bloat risk, and your vet can say whether it applies to your dog. Puppies eat more per pound and more often: see the Mastiff puppy feeding chart.
How the Mastiff compares
Calories per pound fall as dogs get bigger, because RER scales with weight to the 0.75 power rather than linearly. A 190 lb Mastiff needs 17 kcal per pound; a 200 lb Saint Bernard needs 3292 kcal (16 per lb), a 176 lb Newfoundland needs 2991 kcal (17 per lb), a 180 lb Great Dane needs 3042 kcal (17 per lb). The breed ranks 49 of 49 by weight on this site.
Adult weight from Wikipedia breed infobox/body, checked 2026-10-20. Figures are maintenance starting points for a healthy adult; they are not veterinary advice.