How much should you feed your pet?

Free calculator based on the veterinary RER/MER formula. Enter weight, life stage and food type — get daily calories, grams and cups in seconds. No sign-up, no guesswork.

Pet food portion calculator

Veterinary RER/MER formula — daily calories, grams and cups.

Pet

Weight

Life stage & activity

Food type

1164

kcal / day

306 g

food / day (10.8 oz)

3.1

cups / day

2× 153 g

meals / day

RER 727 kcal × 1.6 (adult, neutered/spayed) = 1164 kcal, at 380 kcal/100g. Estimates for healthy pets — always confirm with your veterinarian.

Feeding guides by breed (251)

Every guide opens the calculator pre-set for the breed's typical weight, with portion tables and FAQs.

Toy dogs

Small dogs

Medium dogs

Large dogs

Giant dogs

Cats

How the math works

PetFeedingCalculator uses the formula taught in veterinary nutrition: the Resting Energy Requirement, RER = 70 × (body weight in kg)^0.75, multiplied by a life-stage factor (from 0.8 for a cat on a diet up to 3.0 for a young puppy). The result in kilocalories is converted to grams and cups using the caloric density of the selected food. Read the full methodology on the about page or integrate it via the developer API.