About This Calculator

petportion.site is a free tool that helps you estimate how much to feed your dog or cat.

What it does

Enter your pet's weight, life stage, activity level, and feeding goal, plus the calories listed on the food label. The calculator estimates daily calories, food per day, food per meal, and a sensible treat limit — converted into cups, cans, pouches, or grams.

How the estimate works

The calculation starts from the resting energy requirement (RER), a widely used veterinary nutrition formula, then applies multipliers for life stage, activity, and your goal. All of this runs in your browser; nothing you enter is stored or sent anywhere. You can read the full method in the Guide.

Why we built it

Pet food labels list calories in different units, and feeding guidelines vary widely by pet. We wanted a quick, clear starting point that turns the numbers on the bag into an everyday portion — without sign-ups or guesswork.

Important

This tool provides general estimates only and is not a substitute for veterinary advice. Pets with medical conditions, pregnancy, obesity, or unusual weight changes should follow a veterinarian's feeding plan. See our Terms & Disclaimer.

How it stays free

The site is supported by advertising. See our Privacy Policy for details on cookies and third-party ads, and the Contact page to reach us.