The formula behind the calculator
Vets start with resting energy requirement (RER), the calories a dog burns lying still: RER = 70 × (weight in kg)0.75. They then multiply by a life-stage factor. That's about 1.6 for a typical neutered adult, 1.8 for an intact adult, 1.0 for weight loss, 2 to 3 for growing puppies and more for working dogs. The result is the maintenance energy requirement (MER), your dog's daily calorie target.
Daily calories by weight (neutered adult)
| Dog weight | RER | Daily kcal (×1.6) | Cups at 380 kcal/cup |
|---|---|---|---|
| 5 lb | 129 | 207 | 0.5 |
| 10 lb | 218 | 348 | 0.9 |
| 20 lb | 366 | 585 | 1.5 |
| 30 lb | 496 | 794 | 2.1 |
| 40 lb | 615 | 985 | 2.6 |
| 50 lb | 727 | 1164 | 3.1 |
| 60 lb | 834 | 1335 | 3.5 |
| 70 lb | 936 | 1498 | 3.9 |
| 80 lb | 1035 | 1656 | 4.4 |
| 100 lb | 1223 | 1958 | 5.2 |
Every dog is different
Two dogs of the same weight can need 30% different amounts. Treat the result as a starting point. Weigh your dog every 2 to 4 weeks and check its body condition: you should feel the ribs without pressing hard and see a waist from above. If it's gaining, cut portions by 10%. If it's losing, add 10%. Count treats, chews and table scraps too. They should stay under 10% of daily calories.
Frequently asked questions
How many calories does a dog need per day?
A neutered, moderately active adult dog needs about 1.6 × RER, where RER = 70 × (body weight in kg)^0.75. That is roughly 580 kcal for a 20 lb dog, 980 kcal for a 40 lb dog and 1,650 kcal for an 80 lb dog.
How many cups of food should my dog eat?
Divide daily calories by the kcal per cup on your food bag. Most dry dog foods have 325 to 450 kcal per cup, so a 40 lb neutered adult needing about 980 kcal eats roughly 2½ cups a day of a 380 kcal/cup food.
Should I feed my dog’s current or ideal weight?
Ideal weight. Feeding an overweight dog for its current weight keeps it overweight. Ask your vet for a target weight and use the "needs to lose weight" option.