Dog Food Calculator

Getting your dog's daily portion right is one of the simplest levers you have over their long-term health. Feed too much or too little and problems follow. The portion estimate here aims to keep your dog at a healthy weight.

The calculation starts from the dog's Resting Energy Requirement (RER), with your weight in pounds converted at 0.4536 kg per lb. For dogs of 2 to 45 kg (about 4.4 to 99 lb) it uses the linear formula RER = 30 × (body weight in kg) + 70, which the Merck Veterinary Manual gives for that range; outside it, it uses Merck's formula for any weight, 70 × (body weight in kg)^0.75. RER is then multiplied by an activity factor (1.0 low, 1.4 moderate, 1.8 high) and a life-stage factor (2.0 puppy, 1.0 adult, 0.8 senior), with the combined factor kept between 1 × RER and 3 × RER: feeding below resting energy is a weight-loss plan for your vet to set. For comparison, Merck's maintenance factors are 1.6 × RER for a neutered adult, 1.8 for an intact adult, 1.4 for an obesity-prone dog, and 3 × RER for puppies under 4 months or 2 × RER after that. Dividing the calories by your food's kcal per cup gives cups per day, split into two meals (three for puppies); the monthly estimate assumes 4 cups per pound of food, $2.50 a pound and 30-lb bags.

Any dog with a medical condition or unusual nutritional needs deserves a conversation with your veterinarian before you fix a feeding plan. The numbers printed on a food bag are broad averages and tend to run high, which is a common path to gradual weight gain. Revisit the portion whenever your dog gets older or their activity changes, since needs that fit last year may not fit today.