How to use the dog food calculator
- Enter your dog’s weight. For a dog that needs to lose weight, enter the ideal weight.
- Choose the life stage and activity that best describes your dog.
- Enter the calories from your food’s label — per cup, per kg or per can.
- Set the number of meals and the share of calories for treats.
The formula vets use
Resting energy (RER) = 70 × (body weight in kg)^0.75 kcal/day Daily energy (DER) = RER × life-stage factor Food per day = DER × (1 − treat %) ÷ kcal per cup (or per kg)
Worked example
A 44 lb (20 kg) neutered adult Labrador mix, fed a kibble with 350 kcal per cup, no treats:
- RER = 70 × 20^0.75 = 662 kcal
- DER = 662 × 1.6 = 1,059 kcal per day
- Food = 1,059 ÷ 350 = 3.0 cups a day — 1½ cups per meal for two meals
Life-stage factors
| Dog | Multiply RER by |
|---|---|
| Neutered / spayed adult | 1.6 |
| Intact adult | 1.8 |
| Inactive or prone to weight gain | 1.2–1.4 |
| Weight loss (at ideal weight) | 1.0 |
| Senior, less active | 1.4 |
| Puppy under 4 months | 3.0 |
| Puppy 4 months to adult | 2.0 |
| Working dog, light to moderate work | 2.0–3.0 |
Daily calories by weight (neutered adult)
| Weight | Calories per day | Cups at 350 kcal/cup |
|---|---|---|
| 10 lb (4.5 kg) | 348 kcal | 1.0 |
| 20 lb (9.1 kg) | 585 kcal | 1.7 |
| 40 lb (18.1 kg) | 985 kcal | 2.8 |
| 60 lb (27.2 kg) | 1,335 kcal | 3.8 |
| 80 lb (36.3 kg) | 1,656 kcal | 4.7 |
| 100 lb (45.4 kg) | 1,958 kcal | 5.6 |
Check your dog’s body condition
Numbers are only a starting point — every dog’s metabolism is different. You should be able to feel your dog’s ribs easily under a thin layer of fat, see a waist from above, and see the belly tuck up from the side. If your dog is gaining weight, reduce food by about 10%; if losing weight unintentionally, increase by 10% and check again in two to four weeks. Use a kitchen scale or a proper measuring cup — a “scoop” can hold far more than a cup.
When to ask your vet
- Puppies of large and giant breeds, which need carefully controlled growth.
- Pregnant or nursing dogs, which may need two to four times their normal calories.
- Dogs with kidney, liver, digestive or other medical conditions, or on a prescription diet.
- Any sudden change in appetite or weight.
Changing foods? Mix the new food into the old over about a week to avoid an upset stomach, and recalculate the amount — calories per cup can differ by 100 kcal or more between brands.