The feeding guide printed on most food bags is a rough average that ignores your cat’s actual weight, life stage, and activity level. This calculator uses the resting energy requirement (RER) formula referenced by veterinary nutritionists, then adjusts it for whether your cat is a growing kitten, an active adult, or working toward a healthier weight.
Weigh your cat on a kitchen scale for the most accurate result.
Check your food bag’s label — density varies a lot between brands.
This is a starting point, not a prescription — a cat’s real needs shift with metabolism, health, and how active they actually are. Weigh your cat monthly and adjust up or down if they’re gaining or losing.
How to use the cat food portion calculator
- Enter your cat’s current body weight using the slider (in kg, with lb shown automatically).
- Choose the life stage and goal that matches your cat — neutered adult, kitten, senior, or weight loss/gain.
- Select dry or wet food, then adjust the energy density slider to match the kcal/100g on your food’s label.
- Choose how many meals you feed per day to see the exact portion size per meal.
Frequently asked questions
It depends on weight, life stage, and food type — this calculator gives a personalized estimate, but as a rough baseline, an average 4–5 kg neutered adult cat typically needs around 180–250 kcal per day.
Most adult cats need between 200–300 calories a day, though kittens, active or intact cats, and larger cats need more, while cats on a weight-loss plan or less active seniors typically need less.
Twice-daily feeding works well for most adult cats. Kittens often do better with three or more smaller meals, while a single daily meal can work for some healthy adult cats but may increase begging.
Wet food has far less caloric density than dry kibble — typically 70–100 kcal per 100g versus 300–450 kcal per 100g for dry — so the gram amount needed is much higher for wet food to deliver the same calories.
Kittens need roughly 2–2.5x the calories of an adult cat relative to their weight to support rapid growth. Select “Kitten, under 1 yr” in the calculator for an adjusted estimate.
Select the “Weight loss goal” option for a calorie target roughly 20% below maintenance. Weight loss should still be gradual — no more than 1–2% of body weight per week — and ideally monitored with your vet, since rapid weight loss in cats can cause serious liver problems.
If you’re away for 10+ hours, stick to two meals (morning and night). For cats that get hungry mid-day, consider a third small meal via an automatic timer feeder. The total daily amount stays the same — just divide it by the number of meals you choose.