Cat Food Portion Calculator
Get a daily calorie target for your cat from weight and life stage, using the standard veterinary energy formula.
This is a starting point for a healthy adult cat. Indoor cats often do better at the low end of the range. Adjust over a few weeks based on body condition, count treats toward the total, and check with your vet before changing a kitten's, senior's, or medically managed cat's diet.
How it works
The calculator starts with your cat's resting energy requirement (RER), the standard veterinary formula for how many calories a cat burns at rest: 70 times body weight in kilograms, raised to the power of 0.75. That number is then scaled up for how active your cat's life stage is, since a cat lounging around the house all day needs less than a growing kitten or an intact adult that's still roaming and marking territory.
Worked example: an 11 lb cat converts to 5 kg. Its RER is 70 × 50.75, which comes out to about 234 kcal. For a neutered adult (the 1.2 multiplier), that scales up to 281 kcal a day. Switch a 4 kg neutered adult in instead and the RER drops to 198 kcal, which becomes 238 kcal/day after the same 1.2 multiplier. A 1.5 kg kitten, by contrast, uses the 2.5 multiplier and needs about 237 kcal a day despite weighing far less, because growth burns a lot of energy.
FAQ
Why does a small kitten need almost as many calories as a bigger adult cat?
Growth is expensive. A kitten is building bone, muscle, and organs on top of just staying alive, so the kitten multiplier (2.5) is more than double the neutered adult multiplier (1.2). Pound for pound, a kitten needs a lot more food than a full-grown cat.
My cat is already overweight. Which life stage should I pick?
Use "Weight loss," which applies a 1.0 multiplier on the RER instead of scaling it up. That number is a starting point for gradual, supervised weight loss, not a strict diet plan. Fast weight loss in cats can cause a dangerous liver condition, so loop in your vet before cutting calories significantly.
Do treats count toward the daily total?
Yes. Treats, dental chews, and anything used for training all add calories, and it's easy to lose track of how much they add up to over a day. A good rule of thumb is to keep treats under 10% of the daily total and subtract them from the food portion.
Is this accurate for every cat?
It's a population-level estimate, not a measurement of your specific cat's metabolism. Some cats run higher or lower than the formula predicts. Treat the number as a starting point, watch body condition over a few weeks, and adjust up or down from there, with your vet weighing in on anything involving a kitten, a senior cat, or a medical condition.
For more on getting the amount right, see how much to feed a cat by weight and life stage, how to read a cat food label, and how feeding needs change from kitten to senior.