The rule for dogs is to calculate the resting requirement and then multiply it. For most indoor cats you do not multiply at all — the resting figure is roughly the whole answer, which is why so many well-meaning owners overfeed by a third without noticing.
An average 5 kg indoor cat needs somewhere around 200 kcal a day, and many need less. Around 61% of US cats are overweight or obese, and the two biggest drivers are free-feeding dry food and applying dog arithmetic to a cat. Get the number right, split it across several small meals, and check body condition monthly.
The numbers
| Typical indoor cat, 5 kg | ~200 kcal/day, often less |
|---|---|
| Rule of thumb | About 20 kcal per pound of ideal body weight |
| Formula | RER = 70 × (kg)0.75 — and for most indoor cats that is close to the target, not a starting point to multiply |
| Meals | At least two, 8–12 hours apart. Three or four suits seniors |
| Treats | Maximum 10% of the daily total, taken out of it |
| Weight loss | Vet-supervised. Never starve a cat — rapid loss causes hepatic lipidosis |
Why cat arithmetic is not dog arithmetic
If you have read our dog feeding guide, the method there is to calculate the resting energy requirement and multiply by a life-stage factor — 1.6 for a neutered adult, and so on.
Do not carry that straight across. Veterinary nutrition guidance is consistent that most indoor cats do not need more than their resting requirement to maintain weight, and many need less. An indoor cat's day involves very little of what a multiplier is meant to account for.
For a 5 kg cat, RER works out at about 234 kcal. Applying a 1.6 multiplier as you would for a dog gives 374 — roughly 60% more food than the cat needs. That single mistake, repeated daily, is a large part of why 61% of US cats carry excess weight.
The free-feeding problem, and the study that explains it
Left to themselves, cats graze: 12 to 20 small meals across the day and night is normal, clustered around dawn and dusk.
That grazing instinct is real and worth respecting. The problem is what it does next to a bowl of dry food that never empties.
A 2026 study gave 134 healthy cats aged 7 and over free access to wet, dry and mixed diets using automated weighing feeders. Cats ate around six small meals a day on dry and seven on wet or mixed — the frequency barely changed. What changed was the calories: they consumed the most on an all-dry regimen and the fewest on an all-wet one.
Cats consumed around 6 (dry) or 7 (wet and mixed) small meals over 24 h, clustered around dusk and dawn. They consumed more calories when fed all-dry and fewest calories overall in an all-wet regimen.
Twenty-Four-Hour Feeding Patterns of In-Home Healthy Aging Cats, 2026
The mechanism is calorie density. Dry food runs roughly 350–600 kcal per cup; wet food runs around 165 kcal per can. A small overestimate of dry food is a large overestimate of calories, and the same slip on wet food barely registers.
Doing the sum
Step one. Use your cat's ideal weight, not the current one. If your cat needs to lose weight, feeding the resting requirement of the current weight maintains it.
Step two. RER = 70 × (ideal kg)0.75. Or use the shortcut: about 20 kcal per pound of ideal weight. A 10 lb cat lands near 200 kcal.
Step three. Divide by the calorie density of your food — kcal per cup or per can, printed on the packaging. This number varies enormously between foods, so a generic figure defeats the exercise.
| Cat | Approx. daily kcal | On dry at 400 kcal/cup | On wet at 165 kcal/can |
|---|---|---|---|
| 3 kg / 6.6 lb | ~130–160 | about ⅓ cup | about 1 can |
| 4 kg / 8.8 lb | ~170–200 | about ½ cup | about 1¼ cans |
| 5 kg / 11 lb | ~200–234 | about ⅘ cup | about 1½ cans |
| 6 kg / 13 lb | ~230–270 | about ¾ cup | about 1¾ cans |
Indicative only. Individual metabolism varies substantially, and neutered and older cats generally sit at the lower end. Body condition is the real feedback loop.
The check that beats the formula
Once a month, with your hands:
- Ribs: felt easily under a thin layer, without pressing
- From above: a visible waist behind the ribs
- From the side: the belly tucks up rather than hanging level
Ribs hard to find means reduce the daily amount by about 10% and check again in a month. Obesity in cats is commonly defined as 20% or more above ideal weight, and it is far easier to prevent than to reverse.
Weight loss is a veterinary matter, and this one is not optional
Cats cannot be crash-dieted. A cat that loses weight too fast — or stops eating altogether — can develop hepatic lipidosis, a liver condition that is serious and can be fatal.
The target is around 1% of body weight per week, or 3–4% a month, under veterinary supervision. If your cat needs to lose weight, that is a conversation with your vet before it is a change to the bowl.
And any cat that stops eating for more than a day or two needs to be seen, regardless of weight.
Meals, and how to keep the grazing without the calories
At least two meals, 8 to 12 hours apart. A cat's stomach empties in a few hours and hunger signals arrive by 8 to 10 — one meal a day is not enough.
For senior cats, the American Association of Feline Practitioners suggests three or four small meals.
The practical compromise: measure the full daily amount in the morning, and deliver part of it through a puzzle feeder or scattered across the day. Your cat still grazes; the total is still controlled. That is the arrangement that respects the instinct without paying for it in calories.
Common questions
How much should I feed my cat?
Roughly 20 kcal per pound of ideal body weight — about 200 kcal a day for a 10 lb indoor cat. Divide by the calorie density printed on your food, and check body condition monthly.
Should I multiply the resting requirement like I would for a dog?
Generally no. Most indoor cats do not need more than their resting requirement, and many need less. Applying a dog's 1.6 multiplier can mean roughly 60% more food than the cat needs.
Is free feeding bad?
It suits some cats and drives obesity in many. It also hides appetite changes, which are often the first sign a cat is unwell, and it is not appropriate at all for a cat with diabetes, kidney disease or hyperthyroidism.
Wet or dry?
Both work. Wet food carries far more water and far fewer calories per mouthful, which makes it easier to control weight and helps hydration. Dry is convenient and portions accurately. A combination captures most of both.
How many meals a day?
At least two, 8 to 12 hours apart. Kittens need more. Senior cats often do well on three or four small ones.
My cat needs to lose weight. Can I just cut the food?
No. Rapid weight loss in cats can cause hepatic lipidosis, a serious liver condition. Aim for about 1% a week under veterinary supervision, and see your vet before changing the amount.
What helps, and what does not
The highest-impact change is the number in the bowl, and that costs nothing. These help you hold it.
| The problem | What helps | Note |
|---|---|---|
| Portions are guesswork | A digital kitchen scale | Not from us. Matters more than anything below, especially on dry food |
| Grazes all day, bowl always full | Felt maze puzzle feeder | Delivers part of the measured ration slowly. Battery-free and quiet |
| Eats too fast, then vomits | Anti-gulping maze bowl | Check the maze is wide enough for a cat's face, not a dog's muzzle |
| Barely drinks | Circulating fountain | Never let the pump run dry. Some cats never take to one — keep a bowl too |
| Wet food, or medication | Licking mat | Spread thin. Counts as part of the ration, not extra |
| Crouching to eat, stiff neck | Raised tilted bowl | The bloat caution on raised feeders applies to large dogs, not cats |
A puzzle feeder and a fountain solve two different halves of the same problem. The feeder controls how fast the calories go in; the fountain addresses the water a dry-fed cat is not getting from food. A cat on dry food really does need both, and the fountain is the one people skip.
Also worth reading: why won't my cat drink water and why a cat that has slowed down may be in pain.
Sources
- Twenty-Four-Hour Feeding Patterns of In-Home Healthy Aging Cats Fed Wet, Dry, or a Combination of Wet and Dry Diets Ad Libitum (2026) — 134 cats, automated weighing feeders; meal frequency and caloric intake by diet type
- National Research Council. Nutrient Requirements of Dogs and Cats. National Academies Press, 2006 — RER formula
- 2021 AAHA Nutrition and Weight Management Guidelines for Dogs and Cats
- American Association of Feline Practitioners — Senior Care Guidelines, meal frequency in aging cats
- VCA Animal Hospitals — general feeding guidelines for cats, grazing behavior and free feeding
- Association for Pet Obesity Prevention — US feline overweight and obesity prevalence
- University of California, Davis — retrospective study of 9,062 cats, 2006–2015, obesity prevalence
- Veterinary guidance on hepatic lipidosis and safe rates of feline weight loss
Written by Kindopet Guides. Reviewed 6 September 2026. General guidance, not veterinary advice. Weight loss in cats must be veterinary-supervised, and a cat that stops eating needs to be seen.