Start from resting need, then apply a life-stage factor
RER is the resting energy requirement — what a cat burns doing nothing. Daily need is that figure times a factor for life stage, activity and body condition. A 4 kg cat has an RER near 198 kcal; a neutered indoor adult (factor ~1.2) lands around 240 kcal.
Resting need by weight
| Weight | RER (kcal/day) | Neutered adult (×1.2) |
|---|---|---|
| 2 kg | 118 | ~140 |
| 3 kg | 160 | ~190 |
| 4 kg | 198 | ~240 |
| 5 kg | 234 | ~280 |
| 6 kg | 268 | ~320 |
Treats count. If snacks push past 10% of the daily total, trim the meal portions to match, or the cat quietly gains weight.
The multiplier that turns resting need into daily need
- Life stage. Kittens run 2 to 2.5× RER; neutered adults about 1.2×; intact adults about 1.4×; seniors a little lower.
- Body condition. Feed a lean target at roughly 1.0× RER for weight loss, and a bit above for gain.
- Activity. An indoor-only cat sits at the low end; an active outdoor cat needs more.
Common questions
How many calories does an average cat need per day?
A typical neutered indoor adult cat of about 4 kg needs roughly 200 to 250 kcal a day. Weight sets the resting figure and the life-stage factor adjusts it, so an active or intact cat needs more and a couch-bound one less.
Why is the formula based on weight to the power 0.75?
Metabolism does not scale straight with body weight. Heavier animals burn fewer calories per kilogram, and the 0.75 exponent (Kleiber's law) captures that curve across mammals, which is why it is used instead of a flat calories-per-kilogram rule.
Should I feed for my cat's current weight or target weight?
For a cat at a healthy weight, use current weight. For weight loss, feed to the target weight, not the current one, and cut intake gradually. Never crash-diet a cat, since rapid loss can trigger a dangerous liver condition.
