How much food should a senior cat eat? This guide answers that question as a calculation, step by step: weigh the cat, work out its resting energy requirement, apply the senior factor, and convert the calories into grams. A senior cat of 4 kg needs about 220 calories a day at the usual senior factor of 1.1 — roughly 65 g of a typical dry food — against about 240 for the same cat as a young neutered adult. That difference, about 10%, is the whole of the senior adjustment for a quiet senior: it is real, but it is not a starvation diet, and cutting further than that risks muscle loss. This guide gives the worked examples, the tables, and the stage-by-stage feeding plan for cats from 11 years old onwards.
The senior years are when feeding mistakes show up most clearly, in both directions. A cat that has eaten the same amount since it was two will slowly gain weight as its activity falls, and that extra weight strains joints that are already stiffening and raises the risk of diabetes. A cat that loses its appetite, or whose owner cuts food too hard in the hope of keeping it slim, will lose muscle fast — and muscle lost in old age is very hard to win back. The right amount is the one that keeps weight steady and muscle held: weigh the cat monthly, feel the ribs, and adjust food by about 10% at a time rather than changing everything at once. This guide gives the numbers to start from, and your vet fine-tunes them for your individual cat.
Step 1: weigh your senior cat
Every senior feeding calculation starts with a weight, and the weight must be current — not the weight from a year ago, and not a guess. Weigh the cat monthly, at the same time of day, on the same scales, and write the number down. For a cat, kitchen scales are often the easiest tool: put the cat in a basket or a box on the scales, weigh the basket, and take the difference. Or step on the bathroom scales holding the cat, then step on without it, and take the difference. What you are looking for is the trend over months, not any single reading: a cat that is gaining weight is eating more than it burns, and a cat that is losing weight without a change in food may be ill, and the weight loss is the clue.
Body condition is the second check, and it matters as much as the scales. Feel the ribs: you should feel them easily under a thin layer of fat without pressing hard. Look from above for a visible waist behind the ribs, and from the side for a tummy tuck. Feel the muscles over the spine and hips: in a senior cat, muscle loss is as important as fat, and a cat that is thin but weak has lost muscle, not just fat. A senior cat may look thinner because it has lost muscle, even while it is carrying too much fat — so feel the ribs and the waist, not just the overall shape. The senior cat weight calculator guide explains how to judge body condition in an older cat, and the cat ideal weight calculator gives a starting range from your cat's breed and size.
Step 2: work out the resting energy requirement
Veterinary nutritionists start with the resting energy requirement, or RER — the calories a cat burns at rest in a neutral temperature, doing nothing at all. The formula is: RER equals 70 times body weight in kg to the power of 0.75. You do not need to do the maths by hand — the tables below do it for you — but it helps to know what the tables are doing. A cat of 4 kg has an RER of about 200 calories a day. A cat of 3 kg has an RER of about 160. A cat of 6 kg has an RER of about 270. A cat of 2 kg has an RER of about 115. Those are the calories the cat would burn doing nothing at all, and the daily need is the RER multiplied by a factor for life stage and activity.
Daily needs are then the RER multiplied by a factor: about 1.2 for a typical neutered indoor adult, but about 1.1 to 1.4 for a senior. So a senior cat of 4 kg, with an RER of about 200 calories, needs about 220 calories a day at the 1.1 factor — against about 240 for the same cat as a young neutered adult, and about 500 for the same cat as a kitten. That 10% difference is the whole of the senior adjustment for a quiet senior. A senior cat that is still active — long daily play sessions, climbing, patrolling a garden — needs more than one that sleeps most of the day, and a cat with a health condition may need a different diet entirely, which is a vet decision, not a food-brand decision. The cat calorie calculator works out the same figures for your cat's exact weight, and the cat food calculator converts them into grams for your food.
Step 3: senior cat calories by weight
Use the table below to find your senior cat's daily calories. Find the row nearest the cat's weight, then pick the column that matches the cat: the middle column is the usual starting point for a senior cat, the right-hand column is for a senior that needs to lose weight, and the left-hand column shows what the same cat needed as a young adult, so you can see how much has changed. If your cat is between two rows, take the lower figure first: it is easier to add food to a cat that is losing weight than to take weight off a cat that has gained it.
| Body weight | Young neutered adult (×1.2) | Senior cat (×1.1) | Weight loss (×0.9) |
|---|---|---|---|
| 2 kg | 140 | 130 | 105 |
| 3 kg | 190 | 175 | 145 |
| 4 kg | 240 | 220 | 180 |
| 5 kg | 280 | 255 | 210 |
| 6 kg | 320 | 295 | 240 |
| 8 kg | 400 | 365 | 300 |
Note that calories are the real target and grams are only a translation — different foods have very different calorie densities, so always check the kcal per 100 g on your own bag or tin and work from that. The grams figures below assume a typical dry food at around 350 kcal per 100 g, a common figure, but your food may differ by a wide margin, and the packet's number always wins over this guide's. If your cat is a large breed such as a Maine Coon at 6 to 11 kg, a Ragdoll at 5 to 9 kg, or a Savannah at 5 to 11 kg, use the higher rows of the table; if it is a small breed such as a Singapura at 2 to 3 kg, use the lower rows. Breed matters less than weight, though — the table is by weight, and weight is what the calories follow.
Step 4: convert calories into grams per day
For a senior cat of 4 kg needing about 220 calories a day, that is roughly 65 g of a typical dry food at 350 kcal per 100 g. For a senior cat of 3 kg needing about 175 calories, it is roughly 50 g. For a senior cat of 6 kg needing about 295 calories, it is roughly 85 g. The full table is below, for a typical neutered senior cat at the 1.1 factor.
| Body weight | Calories (senior cat) | Grams of dry food per day |
|---|---|---|
| 2 kg | 130 kcal | 37 g |
| 3 kg | 175 kcal | 50 g |
| 4 kg | 220 kcal | 63 g |
| 5 kg | 255 kcal | 73 g |
| 6 kg | 295 kcal | 84 g |
| 8 kg | 365 kcal | 104 g |
Split the daily amount into two meals — morning and evening — rather than one large meal: two smaller meals are easier on digestion, and a senior cat's digestion is less forgiving than a young cat's. In the late senior years, smaller meals more often — three small meals, or two meals with a small midday snack — can suit a cat that eats slowly or leaves food. If you feed wet food, use the tin's kcal figure to convert: a typical wet food is around 70 to 100 kcal per 100 g, so a 4 kg senior cat needing 220 calories would need roughly 260 g of wet food a day, split across meals. Measure food with scales, not a scoop or a handful: a scoop in one house can be half as much again as a scoop in another, and that hidden extra is often the whole reason a senior cat is overweight. Treats count too: they should stay under 10% of daily calories, which for a 4 kg senior cat is under about 20 calories of treats a day — a few small treats, not a handful. Soft treats are often better for a senior cat with worn teeth.
Feeding a senior cat by stage
The early senior years — from about 11 to about 14 — are usually the easiest to feed. The cat is slowing down but still active, its teeth are mostly sound, and its appetite is steady. The main change is the calorie cut: move from the adult factor of about 1.2 to the senior factor of about 1.1 to 1.4, weigh monthly, and adjust by 10% at a time. A senior food, or an adult food fed in a smaller amount with your vet's agreement, is usually right at this stage. Keep protein good — older cats need protein to hold muscle, and a food that cuts protein to cut calories is the wrong trade. Look for a food labelled complete and balanced, from a manufacturer that employs veterinary nutritionists and runs feeding trials — the label and the company's transparency matter more than the marketing on the front of the bag.
The geriatric years — from 15 on — need more attention. Appetite can fall, teeth can hurt, and the cat may eat slowly or leave food. Warm the food slightly to release smell, offer smaller meals more often, and put the bowl where the cat can reach it easily, without stairs or a high-sided tray in the way. Some seniors develop kidney or other health issues that change the diet entirely — controlled phosphorus, or a prescription diet — which is a vet decision, not a food-brand decision, and therapeutic diets are medicines in food form and should not be chosen by guesswork. Senior cats may be prone to kidney disease, thyroid problems, and dental disease, so mention any change in appetite, thirst, or weight to your vet promptly rather than adjusting food on your own. The senior cat food calculator guide covers the same ground in a different form, and the senior cat age calculator guide explains the life stages the feeding follows.
Common mistakes when feeding a senior cat
The most common mistake is not changing the amount at all: the cat eats what it ate at two years old, its activity falls by a third, and its weight creeps up year by year until its joints and its blood sugar are carrying far more than they were built for. The second is the opposite mistake — cutting food too hard in the hope of keeping the cat slim, and watching it lose muscle instead of fat. Muscle and fat are not the same thing, and a senior cat that is thin but weak is in worse shape than one that is a little heavy but strong. Weigh monthly, feel the ribs and the muscles over the spine and hips, and aim for steady weight with muscle held, not for the lowest number on the scales.
The third mistake is free-feeding — leaving a full bowl of dry food down all day — which makes it impossible to know how much the cat has eaten and hides appetite changes that are often the first sign of illness in a senior cat. The fourth is treat creep: a treat here, a piece of cheese there, and the cat's daily calories rise by a quarter without anyone noticing. The fifth is switching foods suddenly, which upsets a senior cat's digestion more than a young cat's — change foods gradually over a week, mixing the old and new in increasing proportions. The sixth is milk: most adult cats cannot digest lactose well, and milk adds calories the cat does not need. Fresh water should always be available, in several places — senior cats often drink more from a fountain or a bowl away from their food — because good hydration supports kidney health. The adult cat food calculator guide covers the same ground for younger cats, and the senior cat lifespan guide explains what the senior years mean for the whole of a cat's remaining life.
For related reading, see the senior cat food calculator guide, the senior cat weight calculator guide, the cat food calculator, the cat calorie calculator, the senior cat age calculator guide, the adult cat food calculator guide.
Frequently asked questions
How much food should a senior cat eat per day?
A senior cat of 4 kg needs about 220 calories a day at the usual senior factor of 1.1 — roughly 65 g of a typical dry food at 350 kcal per 100 g. A 3 kg senior needs about 175 calories, and a 6 kg senior about 295. Adjust by body condition and your vet's advice — active seniors need more, and quiet ones less.
How do I calculate my senior cat's calories?
Weigh the cat, work out its resting energy requirement — 70 times body weight in kg to the power of 0.75 — and multiply by about 1.1 for a senior cat. A 4 kg cat has an RER of about 200 calories, so at the 1.1 factor it needs about 220 calories a day. The tables above do the maths for weights from 2 kg to 8 kg.
Should I switch my cat to a senior food?
A senior food, or an adult food fed in a smaller amount with your vet's agreement, is usually right from about 11 years old. Look for a food labelled complete and balanced, with good protein to hold muscle — a food that cuts protein to cut calories is the wrong trade. If your cat has a health condition, ask your vet before choosing a special diet.
How many times a day should I feed a senior cat?
Two meals a day, morning and evening, is right for most senior cats. In the late senior years, smaller meals more often — three small meals, or two meals with a small midday snack — can suit a cat that eats slowly or leaves food. Free-feeding, leaving food down all day, makes portion control and appetite monitoring much harder.
Why is my senior cat losing weight?
Unexplained weight loss in a senior cat is always worth checking with a vet — it can be caused by dental pain, kidney or thyroid problems, or other health issues, and it is not solved by simply feeding more. Weigh monthly, note any change in appetite, thirst, or energy, and mention it to your vet promptly rather than adjusting food on your own.
What foods are toxic to a senior cat?
Onions and garlic, chocolate, grapes and raisins, xylitol, alcohol, and lilies — even lily pollen — are all dangerous for cats of any age. If your senior cat eats any of them, call your vet or an animal poison line immediately and tell them what was eaten, how much, and when.
Results on this page are estimates for general information only and are not veterinary advice. If your pet is ill, underweight, overweight, pregnant, or has a health condition, consult your veterinarian before changing diet or care.