A typical healthy adult cat weighs 3.5–5.5 kg (8–12 lb). Use a recent scale reading.
Pick the silhouette that looks most like your cat from above. Need help?
Check the label — for cat food, kcal per can or per cup are most common.
If included, 10% of daily calories are reserved for treats.
Awaiting your cat's details
Enter weight to see your personalised feeding plan instantly.
Step 1 — Resting Energy Requirement (RER): 70 × (weight in kg)^0.75.
Step 2 — Multiplier: A typical neutered indoor cat needs about 1.2× RER — much less than a dog. Intact adults: 1.4×. Active or outdoor cats: 1.6×. Kittens: 2.5×.
Step 3 — Weight management: overweight cats need calories calculated against their ideal weight using a 0.8× factor. Cat weight loss must be slower than dogs — never more than 0.5–1% body weight per week to avoid hepatic lipidosis (fatty liver disease).
Step 4 — Portion translation: we convert the daily kcal into cans, cups or grams based on the food's calorie content.
An average 4.5 kg neutered indoor cat needs only about 180–220 kcal/day — the equivalent of one 5.5oz can of typical wet food. Spaying/neutering drops metabolism by ~25%, and indoor cats burn far fewer calories than wild ancestors. Most "complete and balanced" dry foods pack 380–450 kcal/cup, so the bag's "1/2 to 1 cup" guideline overshoots dramatically.
Never crash-diet a cat. Cats deprived of food for as little as 48 hours can develop hepatic lipidosis — a life-threatening fatty liver condition. Weight loss must be slow: 0.5–1% per week, ideally under veterinary supervision and on a prescription weight-management diet.
Wet food is generally easier to portion accurately because cans are pre-measured, and it has higher water content (helpful for urinary health). However, both can work — what matters most is total daily kcal, not the form.
Most cats overeat when free-fed dry kibble. Measured meals (2–4 per day, split out using puzzle feeders or timed feeders) prevent obesity and align with cats' natural pattern of multiple small "hunts" per day.