Dog Calorie Calculator

How many calories does my dog need per day?

It starts with body weight, not with the bag. Veterinary nutrition uses two steps: a resting energy requirement (RER — the calories a dog burns at rest) and a maintenance energy requirement (MER — RER multiplied by a factor for life stage, neuter status and goal). A dog calorie calculator by weight is really these two lines of arithmetic plus a coefficient table.

RER = 70 × (body weight in kg)^0.75

MER = RER × factor

Worked example, and you can check it against the tool above: a 10 kg dog has an RER of 70 × 10^0.75 = 394 kcal/day. A neutered adult needs 1.6 × that, so 630 kcal/day. This is the same number the MSD Veterinary Manual's own caloric-requirements calculator returns for that dog.

The MER factors we use

Every factor below is taken from a published veterinary source — none of them are our own estimates. The row your dog lands on is highlighted in the result above.

Published MER factors for dogs
Dog's criteria	Factor × RER
Puppy, 0 to 4 months	3.0
Puppy, 4 months to adult	2.0
Neutered adult	1.6
Intact adult	1.8
Inactive / obese	1.3
Weight gain	1.7
Weight loss	1.0

How your answers map to that table

Puppy under 4 months — 3.0, whatever the other answers.
Puppy 4 to 12 months — 2.0, whatever the other answers.
Goal: lose — 1.0.
Goal: gain — 1.7.
Adult, maintain, low activity — 1.3 (the inactive / obese row).
Adult, maintain, normal activity — 1.6 neutered, 1.8 intact.
Adult, maintain, high activity — 1.8. The published table has no adult row above 1.8, so very active and working dogs may need more than this figure; treat it as a floor and watch body condition.
Senior — the published table has no separate senior row, so senior dogs use the adult rows, then activity and goal adjust from there.

From calories to cups or grams

Calories per day divided by your food's energy density gives the portion: kcal per day ÷ kcal per cup = cups per day, or kcal per day ÷ (kcal per 100 g ÷ 100) = grams per day. The figure is printed on the bag, and it varies a lot between foods — which is why this calculator asks for it instead of assuming one.

Scope, limits and what this tool cannot do

MER is an estimate. The source states individual animals can vary by as much as 50% from the predicted value — the range shown with your result is that ±50% band, not a margin we invented.
Treats are capped at 10% of the daily total. That cap is a published rule (10% treats, 90% food), not our suggestion.
Weight loss: the rate quoted with your result is 1–2% of body weight per week, the figure veterinary sources give for dogs.
Dogs only. Cats use a different set of factors and are not covered here.
This page does not diagnose, does not replace a veterinary consultation, and has no account, no sign-in and no saved history — it runs entirely in your browser.

FAQ

How many calories should my dog eat per day?

Whatever the MER says, then adjusted by what the bathroom scales and the body condition score say two weeks later. Start with the number above, hold it steady for a fortnight, and re-check body condition rather than changing the food every few days.

How do I calculate my dog's calorie needs?

Two lines: RER = 70 × (kg)^0.75, then MER = RER × factor. The factor is where most of the judgement sits, and it comes from the published table above — life stage, neuter status, activity and goal pick the row.

Do puppies need more calories than adult dogs?

Yes, substantially. Puppies under four months are calculated at 3.0 × RER and older puppies at 2.0 × RER, against 1.6 × RER for a neutered adult — roughly double for the youngest pups.

Should I change the calories if my dog is overweight?

Yes — set the goal to lose, which moves the factor to 1.0 × RER, and keep treats inside the 10% cap. Aim for 1–2% of body weight per week. Losing faster than that tends to cost lean muscle rather than fat.

How many calories does my dog need by weight — is weight enough on its own?

Weight sets the RER, but it is not the whole answer: a 20 kg neutered, inactive dog and a 20 kg intact, highly active dog sit on different factor rows and end up tens of percent apart. That is why this calculator asks for weight plus five other fields.

Why show the formula instead of just the number?

Because the number is an estimate and the inputs are yours. If you can see which coefficient row was used, you can sanity-check it against what your vet says, and you can tell whether a change came from the dog or from a field you moved.

Sources

RER = 70 × (body weight in kg)^0.75; MER factors for dogs (neutered adult 1.6, intact adult 1.8, inactive/obese 1.3, weight gain 1.7, weight loss 1.0, 0–4 months 3.0, 4 months to adult 2.0); and the statement that individual animals can vary by as much as 50% from predicted values — Merck/MSD Veterinary Manual Caloric Requirements calculator, vetcalculators.com/msd/calories.html, read 5 Oct 2026.
Weight-loss rate: “Ideally, dogs should lose somewhere between 1% and 2% of their initial body weight per week, and closer to 0.5% might be more achievable for morbidly obese dogs”; treats rule: “10% of calories can come from treats and 90% should come from the food” — VCA Animal Hospitals, Creating a Weight Reduction Plan for Dogs, vcahospitals.com, read 5 Oct 2026.
Treats not to exceed 10% of total daily calories, and a healthy rate of weight loss for dogs of 1–2% of body weight per week — Pet Nutrition Alliance calorie calculator, petnutritionalliance.org, read 5 Oct 2026.
Body condition score, 9-point scale, 4–5 of 9 as the ideal band — WSAVA Global Nutrition Committee body condition score charts, wsava.org.
Cross-check performed 5 Oct 2026: a 10 kg dog, BCS 5/9, neutered adult, returns RER 394 kcal/day and MER 630 kcal/day (range 315–945) in both this page and the MSD calculator listed above.