Is this a substitute for veterinary guidance?

No — it's the standard formula veterinarians themselves start from (RER x a life-stage multiplier), but Merck's own reference notes this is "only a starting point" that may need adjusting based on how an individual animal actually responds. Check with a vet, especially for a puppy, kitten, or a pet with a health condition.

My food label gives calories per kilogram of food, not per cup or can — what do I do?

Weigh out one cup or one can of the food (a kitchen scale works), convert your label's per-kilogram figure to that weight, and enter the result as "calories per serving."

Calculator

Dog and Cat Food Calculator

Feeding guides on the bag are a rough starting point at best. This calculator uses the same resting-energy formula veterinarians start from — driven by your pet’s actual weight and life stage — then converts that into servings, bags, and a reorder interval using your own food’s label.

Last checked Sep 17, 2026

Calories per day: 794 kcal
Servings per day: 2.3
Reorder interval: about 26 days

Would rather not track any of this? STUD can reorder it for you automatically.

How we calculate this

Resting Energy Requirement (RER): RER = 70 x (body weight in kg)^0.75 — the standard veterinary formula for either species, which is why weight is the only physical measurement this calculator needs. Merck Veterinary Manual, "Nutritional Requirements of Small Animals".
Life-stage / activity multiplier: Daily energy need is RER multiplied by a factor for life stage and activity — from Merck's own reference table: puppies under 4 months at 3x RER, puppies 4+ months at 2x, adult dogs at 1.4x (weight-prone) to 1.8x (intact), kittens at 2.5x, and adult cats at 1x (weight-prone) to 1.4x (intact). These are starting points a veterinarian may adjust for an individual animal. Merck Veterinary Manual, "Daily Maintenance Energy Requirements for Dogs and Cats".
Calories per serving and servings per bag: Both vary enormously by product and are printed on your own food's label — there's no figure we could source that would be accurate for your pet's actual food, so enter your product's own numbers.

Frequently asked questions

Is this a substitute for veterinary guidance?: No — it's the standard formula veterinarians themselves start from (RER x a life-stage multiplier), but Merck's own reference notes this is "only a starting point" that may need adjusting based on how an individual animal actually responds. Check with a vet, especially for a puppy, kitten, or a pet with a health condition.
My food label gives calories per kilogram of food, not per cup or can — what do I do?: Weigh out one cup or one can of the food (a kitchen scale works), convert your label's per-kilogram figure to that weight, and enter the result as "calories per serving."