Feeding by breed and weight / by weight
How much to feed a 40 lb dog
A 40 lb (18.1 kg) dog has a resting energy requirement of 615 kcal. As a neutered adult with normal activity that becomes 985 kcal a day, or 2¾ cups of a 369 kcal/cup kibble; an intact adult needs 1108 kcal, and a dog that is inactive or gains weight easily 862 kcal. Puppies that currently weigh 40 lb need far more: 1846 kcal under four months, 1231 kcal after.
40 lb dog feeding table
| Life stage / activity | Factor | kcal/day | Cups at 369 | Cups at 300 | Cups at 450 | Grams (96 g/cup) |
|---|---|---|---|---|---|---|
| Neutered adult, normal activity | × 1.6 | 985 | 2¾ | 3¼ | 2¼ | 264 g |
| Intact adult, normal activity | × 1.8 | 1108 | 3 | 3¾ | 2½ | 288 g |
| Adult, inactive or prone to weight gain | × 1.4 | 862 | 2¼ | 2¾ | 2 | 216 g |
| Puppy under 4 months | × 3 | 1846 | 5 | 6¼ | 4 | 480 g |
| Puppy 4 months to adult size | × 2 | 1231 | 3¼ | 4 | 2¾ | 312 g |
RER = 70 × 18.10.75 = 615 kcal. Factors: Merck Veterinary Manual. The 369 kcal/cup column is Purina Pro Plan Complete Essentials Shredded Blend Chicken & Rice (adult dry) (369 kcal/cup per Purina's label); the 300 and 450 columns bracket the usual range printed on adult dry foods. Checked 2026-10-20.
Reading the table
Pick the row that describes the dog, then the column that matches the kcal per cup on your bag — it is printed near the guaranteed analysis, usually as "kcal/cup" or "kcal ME/cup". The puppy rows apply to a puppy that weighs 40 lb today; a growing puppy should be re-weighed and the amount recalculated every two weeks, which the breed puppy charts do for you. The difference between the neutered and intact rows is 123 kcal, roughly 0.3 cups, which is the most common reason a dog fed "by the bag" gains weight.
These are maintenance starting points for a healthy dog. Weigh the dog monthly and check body condition — ribs easy to feel, visible waist — and adjust by about 10% if it is drifting. Pregnant or nursing dogs, working dogs and dogs with a diagnosed condition need a vet's number, not a table.
Other sizes for a 40 lb dog
By the manufacturer's weight bands a 40 lb dog takes a 30 in crate (Medium, 29.7 × 18.6 × 21 in interior; measure the dog's length to confirm), and a Medium rectangle bed (36 × 24 in) on Orvis's chart. Harness size depends on chest girth rather than weight — see the harness size chart.
Breeds whose standard weight includes 40 lb
- Bulldog (40–50 lb)
- Australian Shepherd (35–70 lb)
- English Springer Spaniel (40–60 lb)
- Brittany (30–40 lb)
- Border Collie (31–55 lb)
- Whippet (24–40 lb)