Senior cat nutrition: how calorie needs change after 11
By Josh · Reviewed and updated: 2026-09-17
Buying smaller bags more often is often the right call for an older cat — how long a bag lasts shows the arithmetic.
Part of our feeding guides index — every calculator and chart on the site in one place.
A senior cat needs only about 8% fewer calories than an adult at the same activity level — much less than the 15-25% often quoted, which is a dog figure. The chart below gives senior cat portions by weight.
A senior cat needs only about 8% fewer calories than it did as an adult at the same activity level. That is much less than the 15 to 25% usually quoted — and that figure is about dogs. Cat owners who apply the dog rule of thumb to a senior cat will feed it roughly 18% less than it needs, and the thing they will lose first is muscle. But there is a second half to this that matters more: past about ten, the direction can reverse. For an older cat that is losing weight or muscle, the answer is more food, not less. This page gives the numbers, and then the part that matters more than any of them.
When a cat becomes a senior
Later than a dog, and the threshold is less contested. Guidelines put feline senior status at greater than ten years, with the senior band usually given as eleven to fourteen and geriatric from fifteen. This site uses eleven.
For contrast: a large dog is often considered senior from about seven (see senior dog nutrition). So a nine-year-old dog and a nine-year-old cat are at completely different points in their lives — which is why the feeding advice does not transfer between them either.
How much less: about 8%, and here is the table
Engine-calculated at 380 kcal per 100 g and 120 g per cup, the same basis as the cat portion page. Each row compares adult and senior at the same activity level, which is the only comparison that means anything:
| Body weight | Adult, neutered, typical | Senior | Change |
|---|---|---|---|
| 3 kg | 50 g | 46 g | 8.3% |
| 4 kg | 63 g | 57 g | 8.3% |
| 5 kg | 74 g | 68 g | 8.3% |
| 6 kg | 85 g | 78 g | 8.3% |
| 7 kg | 95 g | 87 g | 8.3% |
The percentage is the same at every weight, because the multiplier is the only thing that moved: 1.2× resting energy for an adult neutered cat at typical activity, 1.1× for a senior.
The AAFP / AAHA feline life stage guidelines put the requirement at about 1.0× resting energy for a middle-aged cat (7 to 10) and 1.10 to 1.25× for a cat over ten — because older cats digest less efficiently, lose muscle, and often need more energy to hold their condition, not less.
Our 1.1× sits at the bottom of that band, which is why the table above reads as a small reduction: compared with a young adult at 1.2×, a middle-aged cat is lower and a senior comes back up. But for a cat in its mid-teens that is losing weight or muscle, the correction is upward, toward 1.2–1.25× — not further down. Do not read the table above as “older cats eat less”. Use the body condition and muscle checks, and if both are falling, feed more and book a check-up.
So how much should a senior cat eat? At eleven years and a typical indoor life, around 8% less than it ate at its peak adult weight — the table above turns that into grams and cups for the common weights. Two adjustments matter more than the percentage: keep the protein up while the calories come down (older cats lose muscle faster than they lose fat), and split the smaller total across two or three meals rather than one. If your cat is losing weight despite eating the calculated amount, that is a veterinary question rather than a feeding one.
What actually changes after eleven
The calorie target moves less than cat owners expect. Everything else moves more:
| What changes | What it means for you |
|---|---|
| Muscle is lost before fat | Lean body mass falls with age, and it can fall while the weight on the scale stays the same. That is why the hands matter more than the number: run them along the spine and over the hips. Prominent bony points on a stable weight is a different cat from the same weight with good muscle over it. The body condition page covers the checks. |
| Kidney function declines | Chronic kidney disease is common in older cats and usually develops quietly. Increased drinking and urination, weight loss and a duller coat are the early signs, and a blood test is what confirms it. If your vet has diagnosed it, their diet plan overrides everything on this page. |
| Hyperthyroidism becomes likely | An overactive thyroid raises metabolism, so the classic picture is an older cat that is hungry all the time and still losing weight. That combination is not a feeding problem and it is not solved by feeding more — it needs a blood test and treatment. |
| Arthritis is under-recognised | Cats hide it. Reluctance to jump onto a favourite surface, missing the litter tray, or no longer grooming the back are often joint pain rather than attitude. Where the food bowl and litter tray are matters more as a cat ages; ramps and low-sided trays help. |
| Protein requirement does not fall | The old idea of putting an older cat on a low-protein diet is outdated. Muscle loss is the main reason a senior's energy requirement drops, so the usual guidance is to keep protein the same or higher while calories come down. Kidney disease is the common exception, and that is a decision for your vet. |
Treats count towards the daily total at any age, and an older cat is often on several small rewards a day for medication or for a flagging appetite. The cat treat calorie calculator works out how much of the day's allowance they take up.
Senior daily grams, ready to feed
The 8% table above shows the change; this one shows the grams you can actually scoop at the senior rate (1.1×RER) with a typical dry food of 380 kcal per 100 g — the same assumption the cat portion calculator uses, so the numbers match what it will return for a senior cat.
| Body weight | RER (kcal) | Senior calories (1.1×) | Senior grams / day |
|---|---|---|---|
| 3 kg | 160 | 176 | 46 g |
| 4 kg | 198 | 218 | 57 g |
| 5 kg | 234 | 257 | 68 g |
| 6 kg | 268 | 295 | 78 g |
Two caveats worth repeating: senior cats lose muscle rather than fat when they lose weight, so a dropping weight at the same portion is a vet check, not a reason to feed more; and if your senior still hunts the hallway at 3 a.m., the adult 1.2× column in the calculator may be the better fit — activity beats age.
Feeding a senior dog as well? See the senior dog nutrition side — the dog math uses NRC senior multipliers (1.35×/1.5×RER). And if your senior cat is losing weight rather than just slowing down, that is usually a symptom rather than a feeding problem — the weight-gain page sets out what to check first.
Senior cat calorie calculator
Enter your cat's weight and the calorie figure from your own food to get the daily amount. The factor used is 1.1× resting energy — the senior cat value from the same engine every other calculator on this site uses.
Reading the result: the factor is 1.1, which is lower than the 1.2 used for a typical adult neutered cat — so it looks like a cut. Treat it as a reference-point difference rather than a rule to feed less: the guidance for cats over ten describes energy needs from 1.10 to 1.25×RER, and the direction of that range is up. Judge your cat by body condition and muscle, not by the number alone.
Checkups that pair with the feeding change
The 8% reduction is a starting estimate, not a prescription — and senior cats are exactly the group where guessing does the most harm. Kidney disease, hyperthyroidism and diabetes all change the calorie equation in opposite directions: a hyperthyroid cat eats more and loses weight while appearing to thrive, while early kidney disease can suppress appetite before any other symptom shows. This is why the senior checkup schedule matters more than any table. Twice-yearly visits with bloodwork from age eleven catch the conditions that silently rewrite the feeding rules, and the vet's weight trend — measured on the same scale at each visit — is the number that keeps the home portions honest between appointments.
The most important line on this page
And keep the earlier warning in force at every age. Never withhold food from a cat to persuade it to accept something else: significant caloric restriction lasting 48–72 hours can cause hepatic lipidosis, which is frequently fatal. In an older cat, a lost appetite is a symptom, not a preference: 24 hours without food - or 48 hours with vomiting, lethargy or jaundice - needs a vet, because the liver cannot wait.
Looking for a senior cat formula? Browse senior cat food on Amazon — check the kcal per 100 g and match it in our cat calculator.
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Frequently asked questions
Is there a senior cat calorie calculator?
Yes — the calculator above works for any cat over eleven. Enter your cat's weight and the kcal figure from your bag, and it returns the daily calories, the grams, and the meals. The senior factor it applies is 1.1× resting energy, which is about 8% below the adult neutered figure — the page explains why that number is so much smaller than the dog one.
How much less should I feed my senior cat?
About 8% less than it ate as an adult at the same activity level — for example 46 g instead of 50 g for a 3 kg cat. That is far less than the 15 to 25% often quoted, which is a figure for dogs. Applying 25% to a cat underfeeds it by roughly 18%.
At what age is a cat a senior?
Guidelines put feline senior status at over ten years, with the senior band usually given as eleven to fourteen and geriatric from fifteen. This site uses eleven. Cats reach senior status later than dogs, so a nine-year-old cat is not in the same place as a nine-year-old large dog.
My older cat is eating well but losing weight. Should I feed more?
No — see your vet. An older cat that is hungry and still losing weight is a classic presentation of hyperthyroidism, and weight loss in a senior cat is also a common sign of kidney disease, diabetes and dental pain. Feeding more does not address any of them.
Do senior cats need less protein?
Generally no. Muscle loss is the main reason a senior cat's calorie requirement falls, so most guidance is to keep protein the same or higher while calories come down. Where a condition limits protein, such as kidney disease, follow your veterinarian's plan instead.
Calculate your cat's daily amount →
How much does a kitten need? →
What changes for a senior dog →
Check body condition, not just weight →
Where the 8% comes from
The roughly 8% reduction in maintenance energy after about eleven years is not a rule of thumb invented here — it reflects the fall in lean body mass and activity that accompanies ageing in cats, which is why the calculated amount has to be revised rather than simply kept constant. The figure on this page is applied to the same two-step resting-energy method used elsewhere on the site, so you can trace every number back to the equation.
Two cautions matter more in senior cats than in younger ones. First, unintended weight loss is not normal ageing — if the amount that used to hold weight no longer does, that is a veterinary question, not a feeding-adjustment question. Second, the 8% is an average: a lean, active twelve-year-old may need no reduction at all, while a sedentary one may need more.
How this page was checked: Numbers traced to NRC (2006), WSAVA and AAHA guidance; units re-derived independently; safety statements limited to the species they were established for. Our review method
Sources
- MSD Veterinary Manual — Nutrition, Small Animals. Resting and maintenance energy requirements used as the denominator throughout this site. msdvetmanual.com
- AAHA — nutritional assessment guidelines for dogs and cats. Body condition scoring, the check that confirms a calculated amount is right. aaha.org
- Tufts University, Cummings School of Veterinary Medicine — Petfoodology. Fat oxidation, rancidity and how storage conditions accelerate them. sites.tufts.edu/petfoodology