How much should your cat eat today?
A few quick questions, the same math the CatCulate app uses, zero sign-up. Get daily calories and a portion guide for the day.
Per day, pick one food for the whole day — not all three.
Guidance for a healthy cat, not veterinary advice — cats with a diagnosed condition, and kittens under 6 weeks, and pregnant or nursing cats need portions from their vet. Adjust ±10% over a few weeks based on body shape.
This is one day, averaged. CatCulate does this every morning for your exact cat — then checks the taurine, moisture, and protein inside those calories, and fixes tomorrow's bowl.
The math, shown honestly
The same math the CatCulate app runs. Resting energy: RER = 70 × (weight in kg)0.75. Adults: RER × activity (low 1.2, moderate 1.4, high 1.6, very high 1.8), × 0.8 if neutered, × 0.95 at 7–11 years. Body shape changes the weight portions are sized for: rounded cats are fed for an ideal weight about 12% lighter (very rounded 20%), lean cats about 10% heavier (very lean 15%). A gentle glide, never a crash diet. Kittens: RER × 2.5 up to 4 months, easing 0.15 a month to 1.3 by their first birthday. Portions divide calories by typical energy density: commercial wet food ~85 kcal / 100 g, kibble ~350, a home-cooked chicken-based bowl ~160.
Real feeding varies by the actual foods in the bowl — which is exactly the part the app manages daily.
Daily calories by weight, at a glance
Same math as the calculator above, worked out for common weights at moderate activity. Calories per day (kcal), rounded.
| Weight | Neutered adult, ideal shape | Not neutered adult, ideal shape | Neutered, 7–11 yrs | Neutered adult, rounded |
|---|---|---|---|---|
| 2 kg | 132 | 165 | 125 | 120 |
| 3 kg | 179 | 223 | 170 | 162 |
| 4 kg | 222 | 277 | 211 | 201 |
| 5 kg | 262 | 328 | 249 | 238 |
| 6 kg | 301 | 376 | 286 | 273 |
| 7 kg | 337 | 422 | 321 | 307 |
Kittens are left out on purpose: a growing kitten's needs change month to month, so use the calculator with the kitten option.
Common questions
How many calories does a cat need per day?
Start from resting energy, RER = 70 × (weight in kg)0.75, then adjust for activity, neutering, age and body shape. A 4 kg neutered adult with moderate activity has an RER of about 198 kcal; × 1.4 for activity and × 0.8 for neutering gives about 222 kcal a day.
How much wet food should I feed my cat?
Divide daily calories by the food's energy density. Typical commercial wet food is around 85 kcal per 100 g, so a 4 kg neutered adult needs roughly 261 g a day. Check your food's label: kcal per 100 g varies a lot between brands.
How much kibble should I feed my cat?
Typical kibble is around 350 kcal per 100 g, so the same 4 kg cat needs roughly 63 g a day. If you mix wet and dry, split the calories between them rather than feeding a full portion of each.
Can I feed my cat home-cooked food?
Calories are the easy part. A home-cooked diet also has to supply taurine, calcium and other nutrients cats cannot go without, and a plain meat bowl does not. Talk to your vet before switching. The CatCulate app checks those nutrients in every bowl you log.
When should I ask a vet instead of using a calculator?
If your cat has a diagnosed condition, is a kitten under 6 weeks, is pregnant or nursing, is losing or gaining weight without an obvious reason, or has stopped eating for a day, call your vet. A calculator is for healthy cats.