What the Dog Food Calculator does
This dog food calculator estimates how much to feed your dog each day. It works out your dog's resting energy from body weight, multiplies it by a factor for age, neuter status, activity or weight goal, and then turns those calories into grams and cups of your own food, using the calorie figure printed on the bag and the weight of your scoop.
It uses the standard veterinary method: resting energy requirement (RER) = 70 x body weight in kg to the power 0.75, from the National Research Council, with life-stage factors from the American Animal Hospital Association's 2021 guidelines. It is an estimate to start from, not veterinary advice, and nothing you enter leaves your browser.
How to use it
- Enter your dog's current weight in kilograms or pounds.
- Choose the life stage that fits: neutered or intact adult, inactive, puppy, pregnant, nursing or working. For weight loss, choose that option and enter the target weight your vet gave you.
- Find the calories on the food label - usually kcal per kg, sometimes per 100 g or per cup - and enter the figure and its unit.
- Weigh one level scoop of the food on a kitchen scale and enter its grams so the result can be shown in cups.
- Set the share of calories you give as treats (10% is the usual maximum) and the number of meals a day, then read the grams and cups per day and per meal.
Reading the results
Daily calories (MER) is the estimated energy your dog uses in a day. The range shown comes from AAHA's range for that life stage; the main figure uses the middle of it. Type a factor of your own if your vet has given you one.
The grams figure is for the main food only, after the treat allowance is taken out. If you give no treats, set treats to 0% and the food portion goes up by the same amount.
Cups depend entirely on your scoop. A "cup" of small dense kibble can weigh half as much again as a cup of large airy kibble, which is why the calculator asks for grams per cup rather than assuming one.
Use the result for two to four weeks, then weigh your dog. If the weight is moving the wrong way, change the portion by about 10% and check again.
Worked example: a 30 kg neutered Labrador
30^0.75 is 12.82, so the resting energy requirement is 70 x 12.82 = 897 kcal a day.
AAHA's factor for a neutered adult is 1.4 to 1.6. The middle, 1.5, gives 897 x 1.5 = 1,346 kcal a day, with a range of 1,256 to 1,436 kcal.
Allowing 10% for treats (135 kcal) leaves 1,211 kcal for the main food. A food with 3,650 kcal per kg supplies 3.65 kcal per gram, so the dog needs 1,211 / 3.65 = 332 g a day - 166 g per meal over two meals.
If one level scoop weighs 105 g, that is 332 / 105 = 3.2 scoops a day, or about 1.6 per meal.
Formulas and scoring rules
- Resting energy requirement
RER = 70 x weight_kg ^ 0.75National Research Council (2006). 1 lb = 0.45359237 kg. For weight loss, the target weight is used.- Daily energy (maintenance)
MER = factor x RERAAHA 2021 canine factors: neutered adult 1.4-1.6, intact adult 1.6-1.8, inactive 1.0-1.2, weight loss 1.0, puppy under 4 months 3.0, 4 months to adult 2.0, last 3 weeks of pregnancy 3.0, nursing 3.0-6.0, work 1.6-11.0.- Calories from the main food
food_kcal = MER x (1 - treats_pct / 100)- Grams per day
grams = food_kcal / kcal_per_kg x 1,000kcal per 100 g is multiplied by 10; kcal per cup is divided by grams per cup and multiplied by 1,000.- Cups and meals
cups = grams / grams_per_cup; per_meal = per_day / mealsShown to the nearest gram and to two decimal places of a cup.
Why the formula is only a starting point
RER scales with body weight to the power 0.75 because energy use follows metabolic body size rather than weight itself: a 30 kg dog needs about 2.7 times the calories of an 8 kg dog, not 3.75 times. The life-stage factor then accounts for growth, reproduction, activity and the lower energy use that typically follows neutering.
Even with the right factor, individual dogs vary widely - breed, coat, temperature, temperament and health all move the figure. That is why AAHA says to adjust intake by monitoring body weight and body condition score. A dog at a healthy condition has ribs you can feel easily under a thin layer of fat and a visible waist from above.
Reading the calories on a dog food label
Complete dog foods state metabolisable energy, usually as kcal per kg and often as kcal per cup or per can as well. Dry kibble is typically several thousand kcal per kg and wet food much less, because most of its weight is water - so the grams of wet food will be far higher for the same calories. If you feed a mix, work out each food's share of the day's calories and convert them separately.
Limitations: what the result does not prove
- Not veterinary advice. Puppies, pregnant and nursing dogs, dogs losing weight and dogs with any medical condition should be fed to a plan from a veterinarian.
- The factors are averages. A particular dog can need noticeably more or less; the body-weight and body-condition check after a few weeks is the real test.
- It does not check that a food is complete and balanced or suitable for the life stage. Choose a food labelled complete for your dog's life stage.
- The cup figure is only as good as your weighed scoop. Measuring cups and scoops vary, and a heaped scoop can hold much more than a level one.
Privacy: where your data goes
Everything you paste, type or drop is processed in this browser tab. It is not uploaded, logged, stored or sent to analytics. Session recording and tag-manager scripts are switched off on this page.
Standards and sources
- National Research Council - Nutrient Requirements of Dogs and Cats (2006) - checked 19 Sep 2026
- AAHA - 2021 Nutrition and Weight Management Guidelines, Box 1: Energy requirement calculations
- WSAVA - Global Nutrition Guidelines
- AAFCO - Reading pet food labels
Frequently asked questions
How much should I feed my dog per day by weight?
Start from calories, not a fixed weight of food. A 20 kg neutered adult needs roughly 930-1,060 kcal a day; at 3,600 kcal per kg of food, with no treats, that is about 255-295 g a day. Enter your dog's weight and your food's calories to get the figure for your bag.
How many calories does my dog need a day?
Multiply 70 by the dog's weight in kg to the power 0.75 to get resting energy, then by a life-stage factor - about 1.4-1.6 for a neutered adult. A 10 kg neutered dog's resting energy is 394 kcal, so it needs about 550-630 kcal a day.
How much should I feed a puppy?
Puppies need far more per kilogram: AAHA uses 3 x resting energy until four months and 2 x from four months until adult size. An 8 kg puppy under four months needs about 1,000 kcal a day. Split it into three or four meals and follow your vet's growth checks.
How many cups of dog food should I feed?
Work out the grams first, then divide by the weight of one level cup of your food. Kibble density varies, so weigh your own scoop: if it holds 100 g and your dog needs 250 g a day, that is 2.5 cups a day.
How much should I feed my dog to lose weight?
AAHA's factor for weight loss is 1.0 times the resting energy of the target weight, not the current weight. For a dog aiming for 25 kg that is about 783 kcal a day. Agree the target and the rate of loss with your vet first.
How many treats can I give my dog each day?
WSAVA and AAHA suggest no more than 10% of daily calories from treats and other foods that are not complete diets. The calculator takes that share off before working out the main food, so the total stays the same.
Is this dog food calculator accurate for every breed?
It uses body weight rather than breed, which is how veterinary formulas work, but individual dogs can differ widely from the average. Treat the result as a starting point, weigh your dog every few weeks, and adjust the portion about 10% at a time.
Last reviewed by the A2Z.Tools team against the sources listed above.
