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Health & Fitness

Pet Food Calculator: Daily Portions for Dogs & Cats

Calculate how much to feed your dog or cat each day based on weight, activity level, and life stage. Uses the standard veterinary RER/MER energy formula.

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Activity Level

Life Stage

Resting energy (RER)662 kcal/day
Daily calorie target (MER)1059 kcal/day
Dry food (≈3.5 kcal/g)303 g / 3.4 cups
Wet food (≈1.0 kcal/g)1059 g

Cup estimates assume standard kibble density. Check packaging caloric content.

How daily calorie needs are calculated

Pet food calculators are based on the Resting Energy Requirement (RER) and a life-stage multiplier. The formula is:

RER = 70 × (body weight in kg)^0.75

This is then multiplied by a factor based on life stage and health status:

Life stage / StatusMultiplier (dogs)Multiplier (cats)
Neutered adult (ideal weight)1.61.2
Intact adult1.81.4
Weight loss (obese prone)1.00.8
Puppy (post-weaning to 4 months)3.02.5
Puppy/kitten (4 months to adult)2.02.0
Pregnant / nursing2.0–3.02.0–3.0
Senior (reduced activity)1.41.1

Understanding food labels

Pet food packaging is required (in the US, by AAFCO) to list the caloric content per unit. Look for the Caloric Content statement, which gives kilocalories per kilogram of food and often per cup or can. Typical values:

  • Dry kibble (dogs): 300–500 kcal per cup (approximately 100g)
  • Wet/canned food (dogs): 150–350 kcal per 400g can
  • Dry kibble (cats): 300–500 kcal per cup
  • Wet/canned food (cats): 150–250 kcal per 156g can

Raw and home-prepared diets have highly variable calorie densities; weigh and calculate rather than guessing by volume.

Weight management signs

Use the Body Condition Score (BCS) rather than just weight to assess your pet:

  • Ideal (BCS 4–5/9): ribs easily felt but not seen; visible waist from above
  • Overweight (BCS 6–7/9): ribs felt with pressure; waist barely visible
  • Obese (BCS 8–9/9): ribs difficult to feel; no visible waist; fat deposits at base of tail

Approximately 60% of cats and 56% of dogs in the US are classified as overweight or obese (APOP 2022). Obesity in pets reduces lifespan and increases risk of diabetes, joint disease, and heart disease.