Free Online Calculators
Calculate daily food needs for dogs and cats
This pet food calculator estimates your dog's or cat's daily energy need from body weight and life stage (puppy or kitten, neutered, intact, inactive or very active). It multiplies the Resting Energy Requirement RER = 70 × weight in kg to the power of 0.75 by the factors from the AAHA 2021 guidelines and shows approximate grams of wet and dry food. Check the result against your pet's weight over time and your vet's advice.
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Start from your dog's ideal body weight and life stage to estimate daily calorie needs, then divide those calories by the energy density of the food (kcal per cup or per can) listed on the label. Split the result across the daily meals and adjust over a few weeks based on body condition and weight changes.
The 80/20 rule describes recipes made of roughly 80% meat, organs and fish and 20% fruit, vegetables and botanicals, with no grain or filler. It's a marketing label used by some brands rather than an official nutritional standard, so still check that the food is complete and balanced.
It depends entirely on the calorie density of the food and your dog's weight, age and activity level, since cups vary widely in kcal from brand to brand. A small, calm dog may be fine on that amount, while a large or active dog will need considerably more.
Pick a food that states it is complete and balanced for your dog's life stage, then match the portion to your dog's calorie needs and watch body condition, coat, stool quality and energy over several weeks. For dogs with allergies, kidney issues or other conditions, let your vet guide the choice.
Avoid raw or undercooked meat, and cured or processed meats such as bacon, ham and sausage or deli meat, because of the salt, fat, spices and bacterial risk. Also skip cooked bones and heavily seasoned meat that may contain onion or garlic.
Under AAFCO naming rules, a food can be named simply after an ingredient, such as "Chicken Dog Food," only if that ingredient makes up at least 95% of the product by weight excluding added water. Lower percentages force different naming, such as "dinner," "with" or "flavor."
There is no single healthiest dog food, because the best choice depends on your dog's age, size, activity level and any medical conditions. Look for a food that is complete and balanced for the right life stage, made by a manufacturer with clear nutritional expertise and quality control.
Be cautious with foods that don't state they are complete and balanced for a life stage, don't publish calorie content or nutrient levels, or come from companies with a history of recalls and no in-house nutritionist. Checking current FDA recall lists and asking your vet is more reliable than brand rankings online.
How much should your dog or cat eat each day? The Pet Food Calculator estimates your pet's daily energy need in kilocalories and converts it into approximate grams of wet and dry food. You choose the species, enter the body weight and pick the life stage. The factors come from the 2021 Nutrition and Weight Management Guidelines of the American Animal Hospital Association (AAHA).
First it works out the Resting Energy Requirement (RER), the energy an animal uses at rest:
RER = 70 × body weight in kg0.75
It then multiplies the RER by a factor for species and life stage. The result is the daily need in kcal. The RER and the factor are shown under the result so you can follow the calculation.
Where the AAHA guidelines give a range (for example 1.4–1.6 for neutered dogs or 1.2–1.4 for neutered cats), the calculator uses one fixed value from that range. The guidelines also note that sedentary and indoor pets often need less. Treat the result as a starting point: weigh your pet regularly and adjust the amount if it gains or loses weight.
For the gram amounts the calculator assumes fixed energy densities: wet food at 100 kcal per 100 g and dry food at 350 kcal per 100 g. Real products differ. If your label gives another value, convert it yourself: daily kcal ÷ kcal per 100 g × 100. At 630 kcal and a kibble with 380 kcal/100 g, that is about 166 g.
If you feed a mix, split the daily calories. At 630 kcal with half wet and half dry food, 315 kcal come from wet food (315 g at 100 kcal/100 g) and 315 kcal from dry food (90 g at 350 kcal/100 g). The calculator has no separate setting for mixed feeding.
RER = 70 × 300.75 ≈ 897 kcal. Times 1.6 gives 1,436 kcal a day, about 410 g of dry food or 1,436 g of wet food. The same dog intact (factor 1.8) needs 1,615 kcal (461 g of dry food); as a very active working dog (2.0), 1,795 kcal (513 g).
RER ≈ 216 kcal, times 1.2 gives 260 kcal: about 260 g of wet food or 74 g of dry food. If the cat is inactive or prone to weight gain (factor 1.0), it is 216 kcal, or 216 g of wet or 62 g of dry food.
RER ≈ 394 kcal, times 3.0 gives 1,181 kcal, about 337 g of dry food at 350 kcal/100 g. From four months the factor drops to 2.0: 787 kcal or 225 g. If the puppy food has a different energy content, use the value on the bag, and enter the current weight again as your puppy grows.
It is an estimate based on a standard veterinary formula. Individual animals can need noticeably more or less. What counts is whether your pet keeps a stable weight and good body condition.
The AAHA guidelines use lower factors for neutered than for intact animals. In the calculator that is 1.6 instead of 1.8 for dogs and 1.2 instead of 1.4 for cats.
The formula does not know breeds, only body weight. From Chihuahua to Great Dane, enter the current weight. For clearly overweight pets, the calculation from the target weight belongs with your vet.
Whenever the weight or the life stage changes, for example after neutering, when a puppy turns four months old or when a dog gets much less exercise than before.
No. The factors apply only to dogs and cats.