How much food should a senior cat eat? It depends on weight, age, and how active the cat is — not on the life stage alone. A senior cat needs a different amount of food from an adult cat, and the amount changes as the senior cat grows or ages, so this guide works it out properly: the resting energy requirement (RER) formula vets use, the calorie table for senior cats at different weights, how much that is in cups and grams, how often to feed, and the mistakes that most often lead to an overweight or underfed senior cat.
The short answer is that a senior cat needs the RER for its current weight, multiplied by a factor for its life stage — and the table below gives that figure at every weight, so you can find your senior cat's row and read the number. The rest of this guide explains what the number means, how to turn it into food, and how to tell whether it is right for your individual cat. Every figure is an estimate: individual cats vary with activity, neuter status, health, and care, and the right amount is the one that keeps weight steady and the cat in good condition.
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. For a senior cat, the factors are the ones in the table below, and the worked example shows how they are used.
For a senior cat of 5 kg, the RER is about 235 calories a day. Multiply by the factor for the senior cat's life stage to get daily needs. The factors are the standard ones used in veterinary nutrition, but they are still starting points: a senior cat that is very active needs more than one that is quiet, and a senior cat that has been neutered typically needs about 10–20% fewer calories than before. The right amount is the one that keeps weight steady: weigh the cat regularly, and if weight drifts up, cut food by about 10% and re-weigh in a month rather than changing everything at once. The cat food calculator works out the figure for your cat's exact weight, and the cat feeding chart by weight gives the same numbers by weight.
Senior cat daily calories by weight
Use the row nearest your senior cat's weight, then pick the column that matches the senior cat's life. If your senior 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 | Senior, typical (×1.2) | Senior, less active (×1.1) | Senior, active or underweight (×1.4) |
|---|---|---|---|
| 2 kg | 140 | 130 | 165 |
| 3 kg | 190 | 175 | 225 |
| 4 kg | 240 | 220 | 275 |
| 5 kg | 280 | 255 | 330 |
| 6 kg | 320 | 295 | 375 |
| 8 kg | 400 | 365 | 465 |
Note that calories are the real target and cups or grams are only a translation. Different foods have very different calorie densities, so always check the kcal per cup or per 100 g on your own bag or tin and work from that. The cups and grams figures in this guide 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 bag's number always wins over this guide's.
How much food in cups and grams per day
For a senior cat of 5 kg, the daily amount is roughly 280 calories, which is about 0.8 cups or about 80 g of a typical dry food at 350 kcal per cup or per 100 g. Work out your own senior cat's figure the same way: take the calories from the table above for your senior cat's weight, divide by the kcal per cup or per 100 g on your own bag, and that is the daily amount in cups or grams. 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 the same senior cat would need roughly 329 g of wet food a day. Mixed feeding is fine as long as the total calories add up — the common mistake is to give a full measure of dry food plus a full tin or pouch of wet food, which roughly doubles the ration.
Split the daily amount into two meals for an adult cat — morning and evening — or use a puzzle feeder so the cat works for its food, which slows eating and adds mental stimulation. 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 cat is overweight.
Feeding a senior cat by age and stage
Senior (from about 11 years). Older cats often need fewer calories — the ×1.1–1.4 range — 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. Some seniors develop kidney or other health issues that change the diet entirely, which is a vet decision, not a food-brand decision. Mention any change in appetite, thirst, or weight to your vet promptly rather than adjusting food on your own.
Two meals a day is the right pattern for a senior cat: a smaller morning meal and a smaller evening meal, at the same times every day, with fresh water always available in several places. If the senior cat eats slowly or leaves food, do not leave the bowl down all day — take it up after 20 minutes and offer it again at the next meal, so you can see appetite changes. A senior cat that stops eating, eats much less, or drinks much more needs a vet check promptly, because appetite and thirst changes are often the first sign of illness in an older animal, and drinking more is often the first sign of kidney disease.
Common feeding mistakes with senior cats
The most common mistake is free-feeding — leaving a full bowl down all day. It makes it impossible to know how much the senior cat has eaten, it hides appetite changes that are often the first sign of illness, and it is the fastest route to an overweight senior cat. The second is feeding by the bag's chart alone: bag charts are generous, because they are written for active animals and rounded up, so treat them as a maximum, not a target. The third is treat creep: a biscuit here, a piece of cheese there, and the senior cat's daily calories rise by a quarter without anyone noticing. The fourth is table scraps, which are often fatty, salty, or simply too many calories, and which teach begging. The fifth is switching foods suddenly, which upsets digestion — change foods gradually over a week, mixing the old and new in increasing proportions. The senior cat food calculator guide and the how many calories should a cat eat per day guide cover the same ground from the schedule and weight sides.
Foods a senior cat should never eat
Some everyday foods are toxic to cats and should never be given, in any amount: onions, garlic, leeks, and chives; chocolate and cocoa; grapes and raisins; xylitol (birch sugar, found in some sugar-free gum, sweets, and peanut butter); alcohol; and raw fish or raw meat that has not been handled safely. Lilies are also highly toxic to cats — even the pollen. If your senior cat eats any of these, call your vet or an animal poison line straight away — do not wait for symptoms and do not try to treat it at home. Keep a note of what was eaten, how much, and when, because the vet will ask.
Choosing a food for a senior cat follows the same rule as for any cat: look for a food labelled 'complete and balanced' for the senior cat's life stage, 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. Price is not a reliable guide to quality, and neither is the ingredient list alone: what matters is the nutrient profile and whether the food suits your individual cat's digestion, coat, weight, and energy. If your senior cat has a health condition, ask your vet or a veterinary nutritionist before choosing a special diet — therapeutic diets are medicines in food form and should not be chosen by guesswork.
For related reading, see the cat food calculator, the cat feeding chart by weight, the senior cat food calculator guide, the how many calories should a cat eat per day guide, the feeding schedule generator, the cat ideal weight calculator.
Frequently asked questions
How much food should a senior cat eat per day?
Use the RER formula with the factor for the senior cat's life stage: about 280 calories a day for a senior cat of 5 kg, which is roughly 0.8 cups or 80 g of a typical dry food. Find your senior cat's weight in the table above for the exact figure, and adjust by body condition and your vet's advice.
How many times a day should I feed a senior cat?
Two meals a day, morning and evening, at the same times every day. One large meal a day is not ideal, and free-feeding — leaving food down all day — makes portion control and appetite monitoring much harder.
How do I know if my senior cat is overweight?
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. If you cannot feel the ribs or there is no waist, the senior cat is probably overweight — cut food by about 10%, keep treats under 10% of daily calories, and ask your vet to set a target weight. The cat ideal weight calculator gives a starting range.
Can a senior cat eat raw food?
Raw diets are possible but need care: they must be complete and balanced, handled hygienically, and agreed with your vet, because an unbalanced raw diet can cause deficiencies and raw meat carries bacteria that can affect cats and people in the house. The raw food calculator gives portion guidance, but it does not replace veterinary advice, especially for kittens, seniors, or cats with health conditions.
What foods are toxic to a senior cat?
Onions, garlic, leeks, and chives; chocolate and cocoa; grapes and raisins; xylitol (birch sugar, found in some sugar-free gum, sweets, and peanut butter); alcohol; and raw fish or raw meat that has not been handled safely. lilies are also highly toxic to cats — even the pollen. 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.
How do I work out the amount for my senior cat's exact weight?
Take the RER for your senior cat's weight — 70 times weight in kg to the power of 0.75 — and multiply by the factor for its life stage from the table above. Or use the cat food calculator, which does the same calculation for any weight, and the cat feeding chart by weight for the full table by weight.
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.