Dog Food Calculator: Daily Calories and Cups
Estimate how many calories and cups of food your dog needs per day from weight and life stage, using the RER formula vets use as a starting point.
Find a sensible starting point for how much to feed your dog each day. The calculator estimates calorie needs from body weight and life stage with the resting energy requirement (RER) formula used in veterinary nutrition, then turns calories into cups using the calorie content printed on your food bag.
How to use this tool
- Enter your dog's weight and choose lb or kg.
- Pick the life stage or activity level that fits best.
- For weight loss, also enter the ideal weight your vet suggested.
- Enter the kcal per cup from the food label.
- Discuss the starting portion with your vet and account for treats before dividing it into meals.
Formula
RER = 70 × (weight in kg)^0.75; daily calories = RER × factor; cups = daily calories ÷ kcal per cup
Selected AAHA starting factors (upper ends where ranges are given): neutered adult 1.6, intact adult 1.8, obesity-prone 1.2, puppy under 4 months 3, older puppy 2. Weight loss uses 1.0 × RER at the ideal weight, and active dogs start at 2.0. A factor from your vet can be entered instead.
Example
A 16 kg (35.3 lb) neutered adult: 16^0.75 = 8, so RER = 70 × 8 = 560 kcal. Multiplying by 1.6 gives 896 kcal a day. With a food that has 448 kcal per cup, that is 896 ÷ 448 = 2 cups a day — for example 1 cup in the morning and 1 in the evening.
Frequently asked questions
Why is this different from the chart on the bag?
Bag charts give one amount for a broad weight band and cannot know whether your dog is neutered or how active it is. A calorie-based estimate tailors the starting point, but your dog's weight trend over a few weeks is what decides.
How accurate is the estimate?
It is a starting point. The Merck Veterinary Manual notes that an individual animal may need as much as 30% more or fewer calories than calculated, which is why a range is shown.
Do treats count?
Yes. WSAVA advises less than 10% of daily calories from treats. Subtract actual treat calories from the meal budget; the cups shown here assume no treats.
When should I talk to a vet first?
Before starting weight loss, and for puppies of large or giant breeds, pregnant or nursing dogs, seniors with health problems or any dog with a medical condition — their needs can differ a lot from the standard factors.
Sources
This tool gives an estimate for general information only. It is not financial, tax, legal or medical advice — check with a qualified professional before you rely on the result.
Last updated: 2026-10-30