Pet Food Portion Calculator

Estimate your dog or cat's daily calorie needs and how many cups of food to feed based on weight and activity level.

Resting Energy (RER)-
Daily Energy Needed-
Food Needed per Day-
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How Pet Food Portions Are Calculated

Veterinary nutritionists estimate a pet's daily calorie needs starting from Resting Energy Requirement (RER), then multiply by an activity factor to get Daily Energy Requirement (DER).

Formula

RER (kcal/day) = 70 × (Weight in kg)^0.75

DER = RER × Activity Factor

How to Use This Calculator

Example

A moderately active 40 lb dog needs roughly 970 kcal/day, which is about 2.8 cups/day of a 350 kcal/cup food.

This is a general estimate - always confirm feeding amounts with your veterinarian.

Frequently Asked Questions

How is pet food portion size calculated?

Based on the pet's weight, life stage, and activity level, referencing the food's calorie density and feeding guidelines.

Why do feeding guidelines on food bags sometimes seem too generous?

Generic bag guidelines don't always account for an individual pet's activity level or metabolism, so adjustments based on body condition are often needed.

How often should portions be reassessed?

Regularly — as pets age, change activity levels, or gain/lose weight, their optimal portion size needs adjustment.

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