Frequently Asked Questions

Our calculator uses the Resting Energy Requirement (RER) formula — RER = 70 × (body weight in kg)^0.75 — the same formula used by veterinary nutritionists worldwide, including at Ohio State University's veterinary school. It then applies Maintenance Energy Requirement (MER) multipliers based on your pet's life stage, activity level, and reproductive status. While individual pets may vary, this method provides a highly accurate starting point that your veterinarian can fine-tune.

Yes, 100% free with no sign-up required. We believe every pet owner should have access to veterinary-grade nutrition tools. The calculator is supported by ads and affiliate partnerships so it can remain free for everyone, forever.

Puppies require significantly more calories per pound of body weight than adult dogs because they're still growing. A puppy under 4 months typically needs about 3× their RER, while puppies aged 4–12 months need about 2× their RER. For example, a 10 kg puppy may need 700–1,050 calories per day. Use our calculator and select "Puppy" as the life stage for a precise recommendation based on your puppy's weight and breed.

The average indoor adult cat (4–5 kg / 9–11 lbs) needs approximately 200–300 calories per day. However, this varies significantly based on activity level, age, and whether the cat is spayed or neutered. Active outdoor cats may need up to 350 calories, while sedentary indoor cats may only need 180–200. Our calculator uses your cat's specific details to provide a personalized recommendation.

Generally yes. Senior pets (dogs 7+ years, cats 11+ years) have slower metabolisms and are typically less active, so they usually need 10–20% fewer calories than younger adults. However, some senior pets with chronic conditions may need more calories. It's important to monitor your senior pet's body condition score and adjust their intake accordingly. Always consult your vet for senior pets.

Several factors influence how many calories your pet needs: (1) Body weight — the primary factor in RER calculation. (2) Breed — some breeds like Huskies have higher metabolisms. (3) Age — puppies/kittens need more, seniors usually need less. (4) Activity level — working dogs need 2–4× more than couch potatoes. (5) Spay/neuter status — altered pets typically need 20–30% fewer calories. (6) Health conditions — diabetes, thyroid issues, and pregnancy all change requirements. (7) Environment — cold-weather pets may need more calories.

Use the Body Condition Score (BCS) system: look at your pet from above — you should see a visible waist. From the side, their belly should tuck up. You should be able to easily feel (but not see) their ribs. If you can't feel the ribs or there's no visible waist, your pet is likely overweight. Over 56% of dogs and 60% of cats in the US are overweight. If your pet needs to lose weight, our calculator can provide a calorie target for gradual, safe weight loss.

Yes! The calorie calculation is based on your pet's energy needs, which remain the same regardless of diet type. Whether you feed kibble, canned food, raw food, or a home-cooked diet, your pet needs the same number of calories. The difference is in calorie density — raw food and wet food are less calorie-dense than kibble, so you may need to feed a larger volume. Once you get your pet's daily calorie target from our calculator, check the calorie content on your specific food's label to determine portion sizes.

Reassess your pet's calorie needs every 1–2 months, or whenever there's a significant change in activity level, health status, or life stage. Puppies and kittens should be reassessed monthly due to rapid growth. Adult pets in a stable routine can be checked every 2–3 months. Always weigh your pet regularly and adjust portions if they're gaining or losing weight unexpectedly.

RER (Resting Energy Requirement) is the number of calories your pet needs at complete rest — just for basic bodily functions like breathing, digestion, and maintaining body temperature. MER (Maintenance Energy Requirement) is the total daily calories needed when accounting for normal activity. MER = RER × a life-stage multiplier. For example, an active adult dog's MER is typically 1.6–1.8 × RER, while a sedentary neutered dog might be 1.2–1.4 × RER.

Most veterinarians recommend feeding adult dogs twice daily and adult cats 2–3 times daily. Puppies under 6 months should eat 3–4 times per day, and kittens should eat 3–4 times as well. Splitting meals helps maintain stable blood sugar, aids digestion, and prevents bloat in large-breed dogs. The total daily calorie amount stays the same — you're simply dividing it into multiple meals.

Treats should make up no more than 10% of your pet's total daily calorie intake. This is often called the "90/10 rule." If your pet needs 500 calories per day, no more than 50 calories should come from treats. Many pet owners underestimate treat calories — a single large dog biscuit can have 100+ calories. Subtract treat calories from your pet's meal portions to avoid overfeeding.

Our calculator provides general calorie guidelines for healthy pets. If your pet has a medical condition such as diabetes, kidney disease, liver problems, thyroid disorders, or food allergies, their nutritional needs may differ significantly. We strongly recommend working directly with your veterinarian or a board-certified veterinary nutritionist for pets with health conditions. The calculator can still serve as a useful starting reference point for the conversation with your vet.

Our calculator supports over 250 dog breeds and cat breeds, from common breeds like Labrador Retrievers, German Shepherds, and Persian cats to rarer breeds like Azawakhs and Norwegian Forest Cats. Each breed profile includes typical weight ranges and breed-specific factors that influence calorie needs. You can browse all supported breeds on our dog breeds and cat breeds pages.

Unlike simple calorie charts or one-size-fits-all recommendations, our calculator uses the scientifically validated RER/MER formula with breed-specific adjustments. We consider 7 different factors (weight, breed, age, activity, spay/neuter status, body condition, and life stage) to provide a truly personalized recommendation. Plus, it's completely free, requires no account, and is available for both dogs and cats in one tool.