Pet Food Calculator: Daily Portions for Dogs & Cats

How to use this tool

1. Select your pet type (dog or cat) and enter their weight.
2. Choose activity level and life stage.
3. See daily calorie needs and portion amounts in grams and cups.

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:

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.