Dog Food Calculator and Cat Food Calculator
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Work out how much to feed your dog or cat each day in calories, cups, cans or grams, with wet and dry feeding, treats and weight loss.
Quick answer: a neutered 30 lb adult dog needs about 794 kcal a day, which is 2.3 cups of a 350 kcal per cup food before treats. This dog food calculator starts from resting energy (70 × kg^0.75), applies a life-stage factor and converts the calories to cups, cans or grams, for dogs and cats.
📐 Formula
RER (kcal/day) = 70 × (weight in kg)^0.75. MER (kcal/day) = RER × life-stage factor. Meal calories = MER × (1 − treat share). Food 2 calories = meal calories × its share, and food 1 gets the rest. Amount = calories ÷ the label figure (cups and cans), or ÷ kcal per kg × 1,000 or ÷ kcal per 100 g × 100 for grams. For weight loss, RER uses the target weight.
How to use the dog and cat food calculator
Choose dog or cat
The buttons change the life-stage options and the energy factors, because cats and dogs use different multipliers.
Enter weight and life stage
Type your pet's current weight in pounds or kilograms and pick the stage. For weight loss, add the target weight so the calculator feeds to that weight.
Enter your food's calories
Type the kcal figure from the label and choose per cup, per can, per kg or per 100 g. Add a second food and its share of calories for wet and dry feeding.
Set treats and meals, then read the amounts
Pick a treat allowance and the number of meals. The result shows the daily amount of each food, the amount per meal and the daily calorie target.
How much should I feed my dog?
Feed by calories, then turn the calories into cups, cans or grams with the number on your food's label. A flat "one cup per 20 pounds" rule ignores how calorie-dense your food is, and kibble varies a lot from bag to bag. The calculator uses the method published by the Pet Nutrition Alliance: resting energy requirement (RER) = 70 × body weight in kg to the power 0.75, then maintenance energy requirement (MER) = RER × a life-stage factor. The same RER formula applies to dogs and cats.
The Pet Nutrition Alliance is blunt about the limits: individual animals can differ from the prediction by as much as 50 percent, so the figure is a starting point. Weigh your pet and judge its body condition every few weeks, then nudge the amount up or down to keep an ideal condition.
Dog food calculator by weight and age: the factors
Weight sets the baseline, and life stage and activity multiply it. These are the published ranges next to the value this calculator uses.
| Life stage | Dog, published | Cat, published | Used here, dog and cat |
|---|---|---|---|
| Weight loss or obese | 1.0 × RER | 0.8 to 1.0 × RER | 1.0 and 1.0, on target weight |
| Inactive or weight-gain prone | 1.2 to 1.4 × RER | 1.0 × RER | 1.2 and 1.0 |
| Neutered adult | 1.6 × RER | 1.2 × RER | 1.6 and 1.2 |
| Intact adult | 1.8 × RER | 1.4 × RER | 1.8 and 1.4 |
| Growth | 2 to 3 × RER | 2 to 3 × RER | 3.0 under 4 months, 2.0 after |
For growth the Pet Nutrition Alliance gives 2 to 3 times RER and says needs fall from about 4 months of age until the pet is fully grown. We use 3.0 under 4 months and 2.0 after that, which are two points inside the published range, not published cut-offs. Nursing pets need much more, 2 to 6 times RER for lactation, and pregnant dogs need more in the third trimester while pregnant cats need more throughout gestation, so use your vet's plan. Our Dog Pregnancy Calculator covers the timing.
Worked example: a 30 lb neutered adult dog
The dog weighs 30 lb, which is 13.6 kg. RER = 70 × 13.6^0.75 = 496 kcal. A neutered adult takes 1.6 × RER, so MER = 794 kcal a day, or 2.3 cups before treats. If 10 percent goes to treats, 79 kcal is the treat allowance and 714 kcal is left for meals. On a food that carries 350 kcal per cup, that is 2 cups a day, or about 1 cup at each of two meals.
Cat food calculator: calories, grams, wet and dry
Cats use lower factors than dogs, 1.2 times RER for a neutered adult and 1.4 for an intact one. Cat food is usually weighed in grams, so choose kcal per kg or kcal per 100 g from the label and the calculator returns grams a day. Say a 10 lb neutered cat weighs about 4.5 kg, RER is 218 kcal and MER is 261 kcal. After a 5 percent treat allowance, 248 kcal is left for meals. If 25 percent of those calories come from an 85 kcal can of wet food and the rest from a 3,800 kcal per kg dry food, that is 0.7 cans and about 49 g of dry food a day. These label values are examples, so enter your own.
How to feed wet and dry food together
Decide what share of calories each food should supply, not what share of weight. Wet food is mostly water, so a can can look like a lot of food while carrying few calories. Enter the dry food as food 1, the wet food as food 2 and its calorie share, and the calculator splits the meal calories between them. If you leave the share blank, food 2 is ignored and the note under the result says so.
How to read calories per cup, can, kg and 100 g
The label figure is what matters, and it differs between brands and between formulas from the same brand. A "cup" is also not standard, so for accuracy weigh the portion in grams. In the UK and Australia the label usually gives kcal per 100 g or per kg, and some show metabolizable energy in kcal per kg. Use that number as printed.
| Label says | Calculator returns | How it works |
|---|---|---|
| kcal per cup | Cups a day | Meal calories ÷ kcal per cup |
| kcal per can | Cans a day | Meal calories ÷ kcal per can |
| kcal per kg | Grams a day | Meal calories ÷ kcal per kg × 1,000 |
| kcal per 100 g | Grams a day | Meal calories ÷ kcal per 100 g × 100 |
Treats and extras: how much of the day they should take
Treats, chews and food toppers all count. The Association for Pet Obesity Prevention's feeding calculator builds them into the daily total, and its general guidance is to keep treats and extras at 10 percent or less of daily calories. Choose 5 or 10 percent and the calculator takes that share out of the meal calories. In the worked example above, 10 percent is 79 kcal, a few small biscuits.
Dog food calculator for weight loss
For weight loss, feed energy for the weight you want, not the weight you have. The Pet Nutrition Alliance gives 1.0 times RER for dogs and 0.8 to 1.0 for cats. Feeding 1.0 times the RER of the current weight overshoots, so the calculator needs a target weight and shows dashes until you enter one that is below the current weight. An 80 lb dog aiming for 65 lb gets 70 × 29.5^0.75 = 886 kcal a day, which is 2.6 cups of a 340 kcal per cup food, where the current weight would suggest 1,035 kcal. Set the target with your vet, because the right pace depends on the dog's health, and recheck its body condition every few weeks.
Puppy food and kitten food
Young animals need 2 to 3 times RER because they are building tissue as well as running a body. Use the under-4-months option for the first few months and the 4-months-to-adult option after that, and weigh a puppy often because its weight changes fast. Large breed puppies are a special case: ask your vet for a growth plan rather than rely on any formula.
Dog food by breed, homemade and raw
Breed does not enter the formula, because the formula uses weight and activity, and two dogs of the same weight can still differ widely. Weight is the thing to enter, whether you own a Labrador or a crossbreed. Homemade and raw diets follow the same calorie math, but you need the kcal for your recipe, which you get by adding up the calories of each ingredient and dividing by the batch weight in grams, then multiplying by 1,000 to get kcal per kg (or by 100 for kcal per 100 g). Complete and balanced homemade recipes are best designed with a veterinary nutritionist. For brands such as Purina, Royal Canin or Hill's, use the calories printed on that product, since the calculator is not tied to one brand.
Signs the amount needs adjusting
- Steady weight gain or loss on the current amount.
- A change in activity, such as long daily walks stopping.
- Spaying or neutering, which lowers energy needs. That is why neutered and intact pets use different factors.
- A change in food, because the calories per cup will not match your old figure.
Move to a new amount gradually over several days. If you are tracking your dog's life stage too, the Dog Age Calculator gives the human-year equivalent, and the Cat Age Calculator does the same for cats. Counting calories for yourself? Try the Calorie Calculator.
Is the pet food calculator different in the UK, Australia and Canada?
The energy formula is the same in all four countries. What changes is the label: UK and Australian foods give kcal per 100 g or per kg, which the unit box handles, and the weight box accepts kilograms. The results are estimates, so check the amount with your vet.
Frequently asked questions
An intact 60 lb dog has a resting energy of about 834 kcal and needs about 1,501 kcal a day at 1.8 times that. If it is neutered the factor is 1.6, which gives about 1,335 kcal. Divide by your food's calories per cup to get the daily amount.
No. Two cups of a 450 kcal per cup food supply 900 kcal, and two cups of a 330 kcal per cup food supply 660 kcal, which is about 27 percent fewer calories. That is why the calculator asks for your food's label figure instead of using a cups-per-pound rule.
A 2 lb kitten under 4 months at 3.0 times resting energy needs about 195 kcal a day. Weigh a kitten every week or so, because the right amount changes quickly as it grows.
Take a 30 lb neutered dog with 714 kcal left for meals after treats. A 25 percent wet share is about 179 kcal, or 2.1 cans of an 85 kcal can, and the other 536 kcal is about 1.5 cups of a 350 kcal per cup kibble. Cut the wet share to 10 percent and the cans drop to about 0.8.
Without it the calculator would feed the weight your pet is now. For an 80 lb dog aiming for 65 lb, that is 149 kcal a day too much, about 17 percent above the 886 kcal target. The box also guards against typos: a target at or above the current weight returns dashes instead of a number.
Make the switch at 4 months. For a 10 lb puppy, resting energy is about 218 kcal, so the 3.0 factor means about 653 kcal a day and the 2.0 factor about 435, a drop of one third. Keep weighing every week or so, and ask your vet to set the pace for a large breed.
Pick kcal per kg in the unit box. A 794 kcal day on a 3,500 kcal per kg food is about 227 g of food.
Count anything that is not the main food: dental sticks, training rewards, chews, toppers and even the cheese used to hide a pill. For a 30 lb neutered dog needing 794 kcal, 10 percent is 79 kcal, so read the kcal on each extra's packet and add them up before you choose 5 or 10 percent.
Not in the formula. A 60 lb neutered Labrador and a 60 lb neutered crossbreed both start at about 1,335 kcal a day. If one of them gains weight on that and the other holds steady, trim the amount for the one that gains after a few weekly weigh-ins, and judge by body condition.
Sources and methodology
The RER formula, the maintenance factors for dogs and cats, the growth range and the 50 percent individual-variation warning come from the Pet Nutrition Alliance table "Calculating Calories Based on Pet Needs". The treat guidance comes from the Association for Pet Obesity Prevention's daily feeding calculator. The 5 percent treat option is our own choice; the Association for Pet Obesity Prevention supports only the 10 percent guidance. Our own choices within those ranges are the two growth factors (3.0 and 2.0), the dog inactive factor (1.2, the low end of 1.2 to 1.4), the cat weight-loss factor (1.0, the top of 0.8 to 1.0) and the cup, can and gram conversions. Feeding to a target weight for weight loss is our own method and is not set out in the Pet Nutrition Alliance table.