A 50 lb spayed or neutered adult needs about 1,160 kcal a day, which is roughly 2¾ cups of a 380 kcal-per-cup kibble with 10% left for treats.
How the dog food calculator works
DogFoodCalc first converts the weight to kilograms (1 kg = 2.205 lb) and works out the resting energy requirement: 70 × kg0.75. It multiplies that by the factor for the life stage you pick to get the daily energy requirement. For weight loss it uses the target weight with a factor of 1.0. The treat percentage is taken off, and the remaining calories are divided by the kcal per cup and the kcal per kg on your food to give cups and grams, then split across meals.
Life-stage factors
| Dog | × RER |
|---|---|
| Puppy under 4 months | 3 |
| Puppy 4–12 months | 2 |
| Adult, spayed/neutered | 1.6 |
| Adult, intact | 1.8 |
| Inactive or overweight-prone | 1.2 |
| Senior | 1.4 |
| Weight loss (at target weight) | 1 |
| Light work | 2 |
| Moderate work | 3 |
| Heavy work | 5 |
Daily calories by weight
| Weight | RER | Neutered adult | Cups (380 kcal) | Puppy 4–12 mo |
|---|---|---|---|---|
| 5 lb (2.3 kg) | 129 kcal | 207 kcal | 0.5 | 259 kcal |
| 10 lb (4.5 kg) | 218 kcal | 348 kcal | 0.9 | 435 kcal |
| 20 lb (9.1 kg) | 366 kcal | 585 kcal | 1.5 | 732 kcal |
| 30 lb (13.6 kg) | 496 kcal | 794 kcal | 2.1 | 992 kcal |
| 40 lb (18.1 kg) | 615 kcal | 985 kcal | 2.6 | 1,231 kcal |
| 50 lb (22.7 kg) | 727 kcal | 1,164 kcal | 3.1 | 1,455 kcal |
| 60 lb (27.2 kg) | 834 kcal | 1,335 kcal | 3.5 | 1,668 kcal |
| 80 lb (36.3 kg) | 1,035 kcal | 1,656 kcal | 4.4 | 2,070 kcal |
| 100 lb (45.4 kg) | 1,223 kcal | 1,958 kcal | 5.2 | 2,447 kcal |
| 120 lb (54.4 kg) | 1,403 kcal | 2,244 kcal | 5.9 | 2,806 kcal |
Factors are the commonly used veterinary starting points; individual dogs vary by 20–30% or more with breed, coat, climate and activity. Check body condition every few weeks and ask your vet about puppies, pregnant or nursing dogs, and dogs with medical conditions.
Frequently asked questions
How much should I feed my dog?
Calculate its daily calories (RER × life-stage factor) and divide by the calories per cup or per kg on the bag. Then watch its body condition and adjust by about 10% if it gains or loses weight.
Where do I find the calories in dog food?
On the bag or can, usually in the guaranteed analysis section, as kcal per kg and kcal per cup or per can.
Are bag feeding guides accurate?
They are a starting range for an average active dog and often overestimate for neutered or less active pets.
Is DogFoodCalc free?
Yes, with no sign-up or ads.
Is this veterinary advice?
No. It uses standard formulas for an estimate; your vet can tailor it to your dog.