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Enter your values and press Calculate.
Enter your dog's weight in pounds, pick the life stage that matches your dog, then enter the calories per cup and grams per cup printed on your food bag, plus how many meals you feed each day. The calculator converts pounds to kilograms, works out the resting energy requirement, applies the life stage factor, sets aside 10 percent of calories for treats, and converts the remaining food calories into cups, grams, and a per meal amount. These are planning estimates, not veterinary advice: if your dog is pregnant, nursing, ill, or gaining or losing weight unexpectedly, ask your vet.
The formula starts with resting energy requirement, or RER, which estimates the calories a resting dog burns in a day: 70 times body weight in kilograms raised to the power 0.75. A 40 pound dog weighs about 18.14 kilograms, giving an RER of about 615 calories. That resting figure is then multiplied by a life stage factor: 2.0 for a puppy, 1.6 for a neutered adult, 1.8 for an intact adult, 1.4 for a senior, 1.0 for weight loss, and 2.0 for a very active or working dog. So the same 40 pound neutered adult needs about 984 calories a day. Showing the formula matters, because most feeding guides hide it and leave you guessing why two dogs of the same weight get different portions.
The daily figure is the maintenance energy requirement (MER): RER times the life stage factor. Maintenance here means the calories needed to hold weight steady at normal activity, not the resting figure alone.
Weigh your dog, or use the weight your vet recorded most recently. Choose the life stage honestly: a neutered adult and an intact adult of the same weight do not need the same food, and a senior dog usually needs less than a younger adult. Read calories per cup and grams per cup from your food bag, since one cup of a dense kibble can hold far more calories than one cup of a light kibble. Enter how many meals you feed, press Calculate, and split the daily cups evenly across those meals. If you switch foods, run the numbers again, because the new food's calories per cup change the portion even when the calorie target stays the same.
Cups are convenient but imprecise, because how firmly you pack the cup changes the amount. Grams are repeatable: the same weight is the same food every time. That is why this calculator gives you both. If your dog's weight is drifting up or down, weigh the food in grams for two weeks before changing anything else, and you will know whether the portion or something else is the cause. A kitchen scale costs little and removes the biggest source of feeding error. Keep the measuring cup only as a backup for travel days.
Cups vs grams is really a question of repeatability: a cup measure varies, a gram weight does not.
Treats count. Vets commonly advise keeping treats within about 10 percent of daily calories, and this calculator already holds that slice back: the cups it shows cover 90 percent of daily calories, leaving 10 percent for treats and chews. If you train with food rewards all day, those rewards are part of the 10 percent, not extra. On days with no treats, you can feed the full calorie target, but do not add the treat calories on top of the full portion on treat days. Small dogs are hit hardest by uncounted treats, because a single biscuit can be a large share of a small daily budget.
For an overweight dog, calculate portions from the weight your vet wants the dog to reach, not the weight it is today. Feeding for the current weight simply maintains the extra weight. For an underweight dog, do the reverse: use the target weight and increase gradually, watching body condition rather than chasing a number on the scale. Body condition score is the check that matters: you should be able to feel ribs under a thin fat cover, see a waist from above, and see a tucked belly from the side. If the ribs are invisible under a thick cover, the portion is too generous, whatever the chart says.
Use the ideal weight as the target and adjust the portion by small steps: that adjustment, checked every two weeks, is safer than one large cut.
Puppies need more calories per pound than adults because they are growing, and they usually eat three or four smaller meals a day rather than one or two large ones. Seniors often need fewer calories as activity falls, but still need enough protein, so a smaller portion of a senior formula is usually better than a large portion of a low quality food. Pregnant and nursing dogs, working dogs, and dogs recovering from illness have very different needs that a single factor cannot capture safely, so treat any calculator result for those dogs as a starting point for a vet conversation, not a final answer. Wet food, raw food, and mixed feeding also change the maths: wet food holds far fewer calories per gram, and raw feeding is usually planned as a percentage of body weight, so convert through calories, not volume, when you mix types.
Puppy feeding by age and weight changes fast: recalculate at each weigh-in, because a puppy that doubles in weight needs far more food, but not twice as much, thanks to the 0.75 power. Dry food amounts and wet food amounts differ because wet food holds much more water per gram, so always convert through calories when you mix dry and wet food.
A 40 pound neutered adult eating a food with 350 calories per cup and 110 grams per cup, fed twice a day: weight in kilograms is 40 / 2.20462 = 18.14. RER is 70 × 18.14⁰.75 = about 615 calories. Daily calories are 615 × 1.6 = about 984 calories. The treat budget is about 98 calories, leaving about 886 food calories. Cups per day are 886 / 350 = 2.53 cups, grams per day are 2.53 × 110 = about 278 grams, and cups per meal are 2.53 / 2 = about 1.27 cups. If the same dog were intact, the factor would be 1.8 and daily calories would rise to about 1,107, which is why the life stage choice matters so much.
It depends on weight, life stage, and the food's calories per cup. Work out daily calories from the RER formula, then divide by calories per cup. A 40 pound neutered adult on a 350 calorie per cup food needs about 2.53 cups of food per day plus a small treat budget. A 20 lb dog on the same food needs about half the portion of a 40 lb dog, while a 50 lb dog needs about a quarter more than the 40 lb dog, because the formula scales with weight to the power 0.75, not in direct proportion.
Multiply resting energy requirement, 70 × weight in kilograms to the power 0.75, by a life stage factor: 2.0 for puppies, 1.6 for neutered adults, 1.8 for intact adults, 1.4 for seniors, and 1.0 for weight loss. A 40 pound neutered adult needs about 984 calories a day.
Most adult dogs do well on two meals a day. Puppies usually need three or four smaller meals. One large meal a day suits very few dogs and can cause hunger, begging, and stomach upset, so split the daily portion across at least two meals for adults.
Use the bag chart as a starting range, not a rule. Bag charts are built for an average dog and often overfeed less active or neutered dogs. Calculate from your dog's actual weight and life stage, then adjust by body condition over two to four weeks.
Neutered dogs usually need fewer calories than intact dogs of the same weight, which is why this calculator uses 1.6 for neutered adults and 1.8 for intact adults. If your dog gained weight after neutering, the portion, not the food brand, is usually the fix.
Puppies need more calories per pound because they are growing, so this calculator uses a factor of 2.0 for puppies against 1.6 for a neutered adult. Feed puppies three or four meals a day, and recalculate as they grow, since a portion that was right at four months is too small at eight months.
Grams are more accurate, because cups vary with how firmly you pack them. Use the grams result with a kitchen scale for everyday feeding, and keep cups as a rough backup. Weighing food is the single easiest way to stop slow weight gain.
Keep treats within about 10 percent of daily calories. This calculator already reserves that slice, so the cups shown cover 90 percent of calories. Training treats, dental chews, and table scraps all count toward the same 10 percent.
Calculate portions from your vet's target weight, not the current weight, and use the weight loss factor. Weigh the dog every two weeks, check body condition, and adjust slowly. Sudden large cuts can leave a dog hungry and are hard to sustain.
Yes, if you convert through calories. Enter the wet or raw food's calories per cup equivalent and grams per cup, and the calculator returns the matching portion. Do not swap cups of kibble for cups of wet food directly, because wet food holds far fewer calories per cup.
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