How many cups of food should I feed my dog per day?

It depends on your dog's weight, age, activity, and the calorie density of the food. Use our calculator for a personalized estimate, then check your food's feeding guide and adjust based on body condition.

Dog Food Calculator

Q: What is RER in dog nutrition?

RER stands for Resting Energy Requirement — the energy a dog needs at complete rest. It's calculated as 70 × (body weight in kg)^0.75 and is the foundation of all veterinary calorie calculations.

Find your dog's ideal daily calorie intake and cup measurement using the RER × MER veterinary formula — the same method used by nutritionists and vets.

📚 Cross-checked against AAHA / WSAVA / AAFP guidelines·Last reviewed: November 2025

Weight (lbs)

Life Stage

Activity Level

Spayed / Neutered?

Calories per Cup of Your Food (kcal) Check the bag's "Caloric Content" section. Average dry kibble ≈ 320–400 kcal/cup.

Daily Feeding Recommendation

—Calories / day

—Cups / day

RER: — kcal | MER Multiplier: —

The RER × MER Formula Explained

All veterinary calorie calculations start with Resting Energy Requirement (RER) — the energy a dog needs just to stay alive at rest. The formula, accepted by the World Small Animal Veterinary Association (WSAVA), is:

RER = 70 × (body weight in kg)^0.75

This is then multiplied by a life-stage and lifestyle factor called the Maintenance Energy Requirement (MER) multiplier. The MER accounts for the extra calories needed for activity, growth, pregnancy, or the calorie savings from spaying/neutering.

MER Multipliers Used in This Calculator

Neutered adult: RER × 1.4–1.6
Intact adult: RER × 1.6–1.8
Puppy: RER × 2.0–3.0 (higher in very young puppies)
Senior / less active: RER × 1.2–1.4
Working/sport dog: RER × 2.0–5.0 (we cap at 1.6× activity)

How to Convert Calories to Cups

Once you know your dog's daily calorie target, divide by the calorie density of your specific food. Every bag of dog food is legally required to list its "Caloric Content" in kcal per cup (and per kilogram). Most dry kibbles range from 300–450 kcal per cup. Wet food is typically 100–200 kcal per can. Always use the number from your specific product, as different brands vary widely.

If you feed a mix of wet and dry food, calculate the proportion from each accordingly. For example, if your dog needs 600 kcal/day and you give one 150-kcal can of wet food, they need (600-150) = 450 kcal from dry food.

Why Calorie Needs Vary So Much Between Dogs

Two dogs of the same weight can have very different calorie needs based on age, activity, reproductive status, and individual metabolism. A 40-lb spayed, sedentary dog might need 700 kcal/day while an intact, working 40-lb dog might need 1,400+ kcal/day. This is why pet food feeding guides on the bag are only rough starting points — they can't account for individual variation.

Body condition score (BCS) is the best feedback mechanism. If your dog's ribs are easily visible, increase food. If you can't feel the ribs with moderate pressure, reduce food. Aim for BCS 4–5 on a 9-point scale.

Frequently Asked Questions

What is RER in dog nutrition?

RER (Resting Energy Requirement) is the baseline calorie need of a dog at complete rest in a thermoneutral environment — the energy needed for basic organ function and cellular metabolism. It is calculated as 70 × (kg)^0.75 and endorsed by WSAVA and AAFCO as the standard basis for canine calorie calculations.

Should I feed my dog based on current or ideal weight?

For overweight dogs, vets often recommend calculating RER based on ideal (target) weight rather than current weight. This naturally creates a caloric deficit to support safe, gradual weight loss. Always consult your vet before putting an overweight dog on a calorie-restricted diet.

How often should I feed my adult dog?

Most adult dogs do best with two meals per day. Puppies under 6 months need 3–4 small meals. Splitting the daily allowance into portions prevents bloat (especially important for large, deep-chested breeds) and helps regulate blood sugar and metabolism.

Do treats count toward daily calories?

Yes. Treats should make up no more than 10% of daily calorie intake. If you give 100 kcal of treats daily, reduce the main meal by 100 kcal. Ignoring treat calories is one of the biggest causes of dog obesity.

My dog seems hungry even after eating the recommended amount — is the calculator wrong?

Not necessarily. Some dogs are just food-motivated regardless of fullness. However, if your dog consistently seems underfed, check their body condition score, confirm the kcal/cup from the food bag, and consult your vet. Certain medical conditions (e.g., diabetes, Cushing's disease) can cause persistent hunger.

Sources: WSAVA Global Nutrition Guidelines 2021; National Research Council (NRC) "Nutrient Requirements of Dogs and Cats" 2006; AAFCO Dog Food Nutrient Profiles; Linder & Mueller (2014) "Caloric intake estimates in dogs" — JAVMA.