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Cat food calculator: How much food does my cat need per day?
Enter your cat's weight, life stage and shape as well as the calories from your food label. The calculator shows you how many kilocalories your cat needs approximately per day and how many grams of wet and dry food that is.
Your result
Attention: Calculated using the gray example values. Enter the kcal from your label so that the gram numbers match your food.
The result is a starting value, not a feeding plan. According to the Merck Veterinary Manual, a cat may need up to 30 percent more or less than another of the same weight. Weigh your cat regularly and adjust the amount.
Your cat on the wall
If you look at the food so closely, you know your cat well. If you want to dedicate a picture to her, your favorite photo will become a portrait.
View cat portraitsThis is how the cat food calculator calculates
It starts with the need for rest, in technical terms Resting Energy Requirement or RER for short. It describes how much energy a healthy cat needs when resting at a comfortable temperature. The formula is: 70 × body weight in kg to the power of 0.75. For a cat weighing 4 kg, that's around 198 kcal per day.
The calculator then multiplies by a factor for life phase and lifestyle. The values come from the Merck Veterinary Manual and the Pet Nutrition Alliance:
| Cat | Factor |
|---|---|
| Kitten | 2.5 (Pet Nutrition Alliance: 2 to 3) |
| Adult, not neutered | 1.4 |
| Adult, neutered | 1.2 |
| Quiet, gains weight easily | 1.0 |
| For losing weight, with ideal weight | 1.0 (Pet Nutrition Alliance: 0.8 to 1.0) |
A neutered, normally active cat weighing 4 kg ends up with around 238 kcal per day. Neither source mentions a separate factor for older cats and very active outdoor cats. The calculator then sticks to the value for adults and tells you that.
From calorie requirements to the number of grams
How many grams that is depends entirely on the food. According to the Cornell Feline Health Center, wet food contains at least 75 percent water, while dry food only contains 6 to 10 percent. That's why there is significantly more energy in 100 g of dry food than in 100 g of wet food. You can find the information in kcal per 100 g on the label or from the manufacturer. If there is a value per kilogram, divide it by 10.
If you feed both, you divide the daily ration according to calories. Half and half means: Half of the kcal comes from wet food, the other half from dry food.
Treats count as well
The Cornell Feline Health Center advises that treats make up no more than 10 to 15 percent of daily calories. The calculator carefully takes the 10 percent. A few chunks of dry food from the daily ration as a reward are also treats, just without extra calories.
Check the figure instead of just calculating
The scales show you whether the quantity is correct. In the veterinary practice, the figure is also assessed using the body condition score. On the scale from 1 to 9, 5 is ideal: the ribs can be felt under a thin layer of fat, and a waist can be seen behind the ribs. This is how the Cornell Feline Health Center describes it. Obesity is the most common nutritional problem in cats there and makes them more susceptible to osteoarthritis and diabetes.
If you change the amount, do so in small increments and re-weigh after a few weeks. What is allowed in the bowl and what is not can be found in our overview What can cats eat?. You can read how much a cat costs in total in the article Cat: Monthly Costs, and how old your cat is in human years can be seen in the Cat Age Calculator.
Frequently asked questions about the cat food calculator
How many grams of food does a cat need per day?
It depends on the food, not just the cat. According to the formula from the Merck Veterinary Manual, a neutered cat weighing 4 kg needs around 238 kcal per day. You calculate how many grams that is using the kcal value on your label, that's exactly what the calculator does.
How many calories does a cat need per day?
As a starting value: rest requirement 70 × weight in kg to the power of 0.75, times 1.2 for neutered and times 1.4 for non-neutered adult cats. Kittens are 2.5 times higher. According to the Merck Veterinary Manual, individual cats can vary by up to 30 percent.
How much wet food and how much dry food should I feed?
Divide the daily ration by calories, not grams. According to the Cornell Feline Health Center, wet food consists of at least 75 percent water, which is why the number of grams in wet food is much higher than in dry food.
How many treats can my cat have?
The Cornell Feline Health Center cites a rule of thumb of no more than 10 to 15 percent of daily calories. The calculator shows you the 10 percent limit in kcal.
My cat is too fat: how much should he eat?
Calculate with the ideal weight, not the current weight. The Pet Nutrition Alliance states 0.8 to 1.0 times the rest requirement for weight loss. You can discuss how quickly your cat should lose weight with your veterinary practice.
Do older cats need less food?
Our sources do not name a fixed factor for this. Older cats are very different. The scales and regular checks at the vet's office will show you whether you should feed more or less.
Sources, accessed on November 5th, 2026: Sherry Lynn Sanderson, Nutritional Requirements of Small Animals, Merck Veterinary Manual, checked by Elizabeth Prouty, as of September 18, 2024 (formula for the need for rest, factors for kittens, neutered and non-neutered cats and for cats that gain weight easily, deviation up to 30 percent). Pet Nutrition Alliance, Calculating Calories Based on Pet Needs. Cornell Feline Health Center, Feeding Your Cat, as of April 30, 2026 (water content of wet and dry food, treats, body condition score).