A vet-formula portion calculator — built on resting energy requirement (RER), not just a flat lookup table. Factors in life stage, body condition, and spay/neuter status.
This calculator starts from your dog's resting energy requirement (RER) — the calories needed at complete rest — using the vet-standard formula RER = 70 × (weight in kg)0.75. That baseline is then multiplied by a factor for life stage, activity level and body condition score to estimate your dog's actual daily calorie needs, rather than relying on a generic weight-to-cups chart.
A growing puppy or a pregnant/nursing dog needs far more calories per pound than a typical neutered adult, while a working dog or a highly active dog burns significantly more than one that's mostly sedentary. Selecting the right life stage and activity level keeps the daily target realistic instead of over- or under-feeding.
Two dogs can weigh exactly the same and still need different amounts of food, because weight alone doesn't say whether a dog is lean, ideal, or carrying extra weight. Body condition score (BCS) — how easily you can feel the ribs and see a waist from above — adjusts the calorie target up slightly for a dog below ideal condition, and down for one above it, so the recommendation matches the dog in front of you, not just the number on the scale.
The results show a daily calorie target, the equivalent portion in cups, cans or grams based on your food's calorie density, a per-meal breakdown, and a treat allowance capped at 10% of daily calories — a common guideline vets use to avoid displacing balanced nutrition. If you've marked the entered weight as a goal weight, you'll also see an estimated timeline for reaching it safely.
The daily calorie target works the same way regardless of food type — what changes is the calories-per-serving number you enter. Dry kibble is calorie-dense, so portions look small; wet food has a much lower calorie density per can due to its water content, so portions look larger for the same number of calories. To feed a mix, calculate the portion for each food separately using its own calorie density, then divide the daily calorie target between the two in whatever split works for your dog — many owners feed a base of dry food with a portion of wet mixed in for palatability, without exceeding the combined daily total.
This calculator gives a starting point, not a fixed number carved in stone — a dog's real-world calorie needs shift with metabolism, season, and life changes. Ribs that are difficult to feel under a layer of fat, or a waist that's no longer visible from above, usually mean it's time to dial the portion back. On the other end, ribs that are sharply visible with no fat cover, or a dog that seems constantly hungry and losing weight, usually means the portion is running low. Re-checking body condition every couple of weeks after any change is the most reliable way to know whether the target needs adjusting, rather than relying on weight alone.
If the new calculated portion is noticeably different from what your dog currently eats — especially a change in food brand or type — introduce it gradually over 5 to 7 days rather than switching all at once. A common approach is mixing roughly a quarter of the new amount with three-quarters of the old on day one, and shifting the ratio a little further each day. This gives the digestive system time to adjust and helps avoid stomach upset, particularly when moving between very different calorie densities.
How is the daily calorie target calculated? It uses RER = 70 × (weight in kg)0.75, then multiplies by a factor for life stage, activity level and body condition score.
Is this free to use? Yes, completely free with no account required, and it runs entirely in your browser.
Can I use this for puppies? Yes — select the Puppy life stage for a higher growth-appropriate multiplier. For very young or toy-breed puppies, also check with your vet.
Does this replace advice from a vet? No. It's a starting estimate — dogs with medical conditions, extreme sizes, or a body condition score far from ideal should be assessed by a veterinarian.
What is body condition score (BCS) and why does it matter? BCS rates how visible a dog's ribs and waist are, from 1 (very thin) to 9 (obese). It fine-tunes the calorie target so the recommendation reflects your dog's actual condition, not just their weight.
How does the treat allowance work? It follows the commonly used 10% rule — treats and extras shouldn't make up more than 10% of a dog's total daily calories, keeping the rest as balanced, complete nutrition from the main food.
Can I mix wet and dry food? Yes — calculate the portion for each food separately using its own calories per serving, then split the daily calorie target between them in whatever ratio suits your dog.
How often should I recalculate my dog's portion? Recalculate when weight changes by more than a few percent, activity level changes, after spaying or neutering, or every few months for a growing puppy, since RER changes as body weight changes.
Why does my dog still seem hungry on this amount? Some dogs eat quickly and feel hungry from habit rather than genuine energy need. Try splitting the same total into more meals or adding low-calorie fiber before increasing total calories — check body condition score first.
Does breed affect the daily calorie target? Breed isn't a direct input in the formula, but breed-typical activity and body type often guide which activity multiplier and body condition adjustments fit best.
Disclaimer: This tool provides a general estimate only and is not a substitute for professional veterinary advice. Always consult a veterinarian for guidance specific to your dog's health, breed, and medical history.