What should a senior cat eat? A senior cat — usually a cat from about 11 years old — needs a different diet from a younger adult: fewer calories, because it moves less, but still good protein to hold muscle, and attention to hydration, kidneys, and weight. This guide is the senior cat diet guide in words: how many calories a senior cat needs at each weight, how much that is in grams, what to look for in a senior food, how to feed a senior cat that eats less or drinks more, and when a change in appetite or thirst is a reason to call the vet. Every figure is an estimate, and every diet change for a senior cat should be agreed with a vet.
The senior years are when diet matters most and when it is hardest to get right: a senior cat may eat less, or eat the same amount and gain weight because it moves less; it may drink more, which is often the first sign of kidney disease; and it may develop a health condition that changes the diet entirely. The aim of this guide is to give you the numbers and the judgement to feed a senior cat well, and to know when the numbers are not enough and the vet needs to decide.
How many calories does a senior cat need?
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. Daily needs are then the RER multiplied by a factor for life stage and activity: about 1.2 for a typical neutered indoor adult, about 1.1 to 1.4 for a senior, and about 1.4 to 1.6 for an active or outdoor cat. A senior cat usually needs the lower end of that range, because it moves less — but a senior cat that is still active, or that is losing weight, may need the higher end, and that is a judgement for your vet, not for a chart.
| Body weight | Neutered adult (×1.2) | Senior, typical (×1.2) | Senior, less active (×1.1) | Senior, active or underweight (×1.4) |
|---|---|---|---|---|
| 2 kg | 140 | 140 | 130 | 165 |
| 3 kg | 190 | 190 | 175 | 225 |
| 4 kg | 240 | 240 | 220 | 275 |
| 5 kg | 280 | 280 | 255 | 330 |
| 6 kg | 320 | 320 | 295 | 375 |
| 8 kg | 400 | 400 | 365 | 465 |
Use the row nearest your cat's weight, then pick the column that matches the cat's life. If your senior cat is losing weight, do not simply feed more: weight loss in a senior cat is often a sign of illness, especially kidney disease or thyroid problems, and it needs a vet check before the diet is changed. If your senior cat is gaining weight, cut food by about 10% and re-weigh in a month. The right amount is the one that keeps weight steady: weigh the cat monthly, and feel the ribs — you should feel them easily under a thin layer of fat. The senior cat food calculator guide gives the same numbers in calculator form, and the cat food calculator works out the figure for your cat's exact weight.
How much food in grams per day
| Body weight | Calories (senior, typical) | Grams of dry food per day |
|---|---|---|
| 2 kg | 140 kcal | 40 g |
| 3 kg | 190 kcal | 54 g |
| 4 kg | 240 kcal | 69 g |
| 5 kg | 280 kcal | 80 g |
| 6 kg | 320 kcal | 91 g |
| 8 kg | 400 kcal | 114 g |
The grams figures assume a typical dry food at around 350 kcal per 100 g — a common figure, but your food may differ, and the packet's number always wins over this guide's. Split the daily amount into two meals for a senior cat, morning and evening, at the same times every day, and offer the food in a quiet place where the cat is not disturbed. 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 about 250 calories would need roughly 300 g of wet food a day. Wet food has a second advantage for senior cats: it adds water to the diet, which supports kidney health. Mixed feeding is fine as long as the total calories add up. Measure food with scales, not a scoop, and keep treats under 10% of daily calories.
What to look for in a senior cat food
Look for a food labelled 'complete and balanced' for senior cats, or for adult cats if your vet agrees, from a manufacturer that employs veterinary nutritionists and runs feeding trials. A senior food is usually a little lower in calories than an adult food, a little higher in protein to hold muscle, and often has added fibre for digestion and added omega-3 fatty acids for joints — but the label matters less than the nutrient profile and whether the food suits your individual cat's digestion, coat, weight, and energy. Price is not a reliable guide to quality, and neither is the ingredient list alone.
Some senior cats develop kidney disease, and kidney diets are lower in protein and phosphorus than ordinary foods — but a kidney diet is a therapeutic diet, and it should only be fed on veterinary advice, after blood and urine tests have shown that the kidneys need it. Feeding a kidney diet to a healthy senior cat is not a good idea, because it is lower in protein than a healthy senior cat needs, and a healthy senior cat needs good protein to hold muscle. The same applies to any therapeutic diet: it is a medicine in food form, and it should not be chosen by guesswork. If your senior cat has a health condition, ask your vet or a veterinary nutritionist before choosing a special diet.
Feeding a senior cat that eats less
A senior cat that eats less is common, and it has many causes: dental pain, a reduced sense of smell, nausea from kidney disease, or simply a slower metabolism. The first step is a vet check, not a change of food — appetite loss in a senior cat is often the first sign of illness, and it needs to be investigated before the diet is changed. If the vet finds no illness, there are practical steps that help: warm the food slightly, to release its smell; offer smaller, more frequent meals; offer wet food, which is often more appealing than dry; and offer the food in a quiet, warm place where the cat is not disturbed. Do not leave food down all day, and do not offer a different food at every meal — a senior cat that is offered a new food every time it refuses one learns to refuse food, and the owner ends up with a cupboard of open tins and a cat that still will not eat.
A senior cat that eats less and loses weight needs a vet check promptly, because weight loss in a senior cat is often a sign of illness. A senior cat that eats less but holds its weight may simply need fewer calories, and the amount should be adjusted by body condition rather than by the chart. Weigh the cat monthly, write the number down, and compare it over time — the line over months is what matters, not any single reading. The when is a cat considered a senior guide explains the senior boundary, and the senior cat age calculator guide gives the human-age chart for senior cats.
Water, kidneys, and the senior cat diet
Water matters more in a senior cat's diet than in a younger cat's, because kidney disease is common in older cats and good hydration supports kidney health. Keep fresh water available in several places, in clean bowls, away from the litter tray, and consider a water fountain if your cat prefers running water — many cats drink more from a fountain than from a bowl. Wet food adds water to the diet, which is another reason it suits senior cats: a cat eating wet food takes in considerably more water than one eating dry food alone. Do not add salt to the diet to make the cat drink more — that is not a safe way to increase water intake, and it can harm a cat with kidney or heart disease.
Drinking more is often the first sign of kidney disease, so mention it to your vet promptly rather than assuming it is just old age. A vet check with blood and urine tests can show how the kidneys are working, and if kidney disease is found, the diet will change — usually to a therapeutic kidney diet, lower in protein and phosphorus, fed on veterinary advice. Early detection matters: kidney disease caught early can be managed for years, while kidney disease caught late is much harder to treat. That is why a senior cat should see a vet twice a year, with blood and urine tests when the vet recommends them.
Common senior cat diet mistakes
The most common mistake is keeping the senior cat on the same food and the same amount as when it was an adult: a senior cat usually needs fewer calories, because it moves less, and the same amount that kept an adult cat steady will make a senior cat gain weight. The second is feeding a kidney diet to a healthy senior cat, which is lower in protein than a healthy senior cat needs. The third is switching foods suddenly, which upsets digestion — change foods gradually over a week, mixing the old and new in increasing proportions. The fourth is free-feeding, which hides appetite changes that are often the first sign of illness. The fifth is ignoring thirst: a senior cat that drinks more needs a vet check, not a change of food. And the sixth is forgetting to weigh the cat: weigh it monthly, and feel the ribs, so slow weight gain or loss does not creep up unnoticed. The how to switch cat food safely guide explains how to change foods gradually, and the how much food should a senior cat eat guide gives the calorie tables for senior cats by weight.
For related reading, see the senior cat food calculator guide, the how much food should a senior cat eat guide, the cat food calculator, the how to switch cat food safely guide, the when is a cat considered a senior guide, the senior cat age calculator guide.
Frequently asked questions
How much food should a senior cat eat per day?
A typical senior cat of 4 kg needs about 250 calories a day, which is roughly 70 g of a typical dry food at 350 kcal per 100 g. Use the table above for your cat's weight, and adjust by body condition and your vet's advice — a senior cat that is still active, or that is losing weight, may need more, and that is a judgement for your vet.
Should I change my cat's food when it becomes a senior?
Usually yes — older cats often need fewer calories because they move less, but they still need good protein to hold muscle. A senior food, or an adult food fed in a smaller amount with your vet's agreement, is usually right. If your cat has a health condition, ask your vet before choosing a special diet.
Why is my senior cat drinking more water?
Drinking more is often the first sign of kidney disease, which is common in older cats, so mention it to your vet promptly rather than assuming it is just old age. A vet check with blood and urine tests can show how the kidneys are working, and early detection matters — kidney disease caught early can be managed for years.
Should a senior cat eat wet food or dry food?
Either can be right, but wet food has an advantage for senior cats: it adds water to the diet, which supports kidney health, and it is often more appealing to a cat that eats less. Mixed feeding is fine as long as the total calories add up. Use the tin's kcal figure to convert, and measure food with scales.
What if my senior cat will not eat?
A senior cat that stops eating, or eats much less, needs a vet check promptly — appetite loss in a senior cat is often the first sign of illness. If the vet finds no illness, try warming the food slightly, offering smaller, more frequent meals, and offering wet food in a quiet, warm place. Do not offer a different food at every meal.
How often should a senior cat see a vet?
Twice a year, with a weight check, a dental check, and a general examination at each visit, plus blood and urine tests when the vet recommends them. A senior cat that sees a vet regularly has problems caught early, when they are cheapest and easiest to treat.
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.