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Dog food calculator
Work out how many calories your dog needs each day, and how much of your dog's food that is.
Your dog's daily calories and portion sizes will show here.
A starting point, not a prescription. Dogs with health conditions need a plan from their vet. Last reviewed October 6, 2026.
How this calculator works
Vets estimate a dog's energy needs in two steps. First comes the resting energy requirement (RER), the calories needed just to keep the body running:
RER = 70 × (body weight in kg)0.75
Then RER is multiplied by a factor for life stage and lifestyle to get the daily calories. The factors below come from the Pet Nutrition Alliance's veterinary calorie sheet.
| Dog | Daily calories |
|---|---|
| Adult, spayed or neutered | 1.6 × RER |
| Adult, not spayed or neutered | 1.8 × RER |
| Inactive or prone to weight gain | 1.2–1.4 × RER |
| Weight loss (use ideal weight) | 1.0 × RER |
| Growing puppy | 2–3 × RER |
| Pregnant | 1.6–2.0 × RER |
To turn calories into food, the calculator divides by the calories in your food. Example: a neutered 40 lb (18.1 kg) dog has an RER of about 615 kcal, so it needs about 985 kcal a day. With a dry food at 380 kcal per cup, that's about 2.6 cups a day.
Calories vary a lot between foods
One cup of one dry food can have far more calories than a cup of another, so feeding "the same amount" after switching brands can change your dog's intake a lot. Always use the kcal figure printed on your specific bag or can.
Every dog is different. Use the result as a starting point, weigh your dog every few weeks, and adjust by about 10% if they gain or lose weight you didn't plan for. Treats count too: keep them to about 10% of the daily calories.
Questions people ask
How much should I feed my dog a day?
It depends on weight, life stage and the calories in the food. A typical spayed or neutered adult needs about 1.6 times its resting energy requirement. Enter your dog's weight and the kcal per cup from your food bag above to get the amount in cups.
How many calories does a dog need per day?
As a rough guide, a spayed or neutered adult dog of 10 lb needs about 350 kcal, 20 lb about 585 kcal, 40 lb about 985 kcal and 60 lb about 1,335 kcal a day. Active dogs need more, and dogs that gain weight easily need less.
Should I use the feeding guide on the bag?
The bag's guide is a reasonable start, but it covers a wide range of dogs. Calculating from your dog's weight and life stage, then adjusting based on weigh-ins, is usually more accurate.
How much should I feed my dog to lose weight?
Weight-loss plans are usually based on the dog's ideal weight rather than its current weight, at about 1.0 times RER. Ask your vet for a target weight first, and aim for slow, steady loss.
How many times a day should I feed my dog?
Most adult dogs do well on two meals a day. Puppies usually eat three or four smaller meals. The calculator splits the daily amount across the number of meals you choose.