Pet Food Portion Calculator
Calculate your pet's daily calorie needs using the standard veterinary Resting Energy Requirement formula. Fast, free, and fully client-side.
Calculator Inputs
How the Pet Food Portion Calculator Works
Calculates daily caloric needs (kcal/day) for dogs and cats using the Resting Energy Requirement (RER) formula from veterinary nutrition guidelines, scaled by a life-stage/activity multiplier. Outputs calories, not cups or grams — food density varies by brand, so convert the result using the kcal-per-cup figure printed on your specific food's packaging.
Formula
RER = 70 × (Body Weight in kg)^0.75, then Daily Calories = RER × Life-Stage Factor
RER estimates the energy an animal burns at rest; the life-stage factor scales that up for real-world activity and growth needs, per WSAVA global nutrition guidelines.
Calculation Example
A 10kg neutered adult dog: RER = 70 × 10^0.75 ≈ 70 × 5.62 ≈ 393. Daily calories = 393 × 1.4 ≈ 550 kcal/day.
Frequently Asked Questions
Why doesn't this tell me how many cups to feed?
Calorie density differs by brand and formula — check your food bag's "kcal/cup" or "kcal/kg" figure and divide your daily calorie result by it to get the right portion.
Is this accurate for every pet?
It's a solid starting estimate; pets with medical conditions, extreme activity levels, or weight-management needs should get a vet-tailored feeding plan.
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