- If you have an average cat, meaning one that's not a kitten, pregnant, lactating or overweight and not at an advanced age, figuring out calories is pretty simple. Average cats needs about 20 to 30 calories per pound of body weight per day. So if you have a seven-pound cat, it needs about 210 calories a day (seven pounds x 30 calories per pound = 210 calories).
- If your cat is pregnant, she'll need more calories than average. Feline pregnancies last about nine weeks. By the end of the pregnancy, your cat should be eating 25 percent more calories than she ate before she was pregnant. Slowly increase the amount of calories you provide your pregnant cat over the nine weeks. Your cat will develop a large, full belly at the end of pregnancy that can restrict how much she can comfortably eat. At that time, it's best to provide her with the proper calories in several small meals. At the end of the nine weeks, your cat will stop eating. This is normal and indicates that birth is imminent.
- Being overweight has a drastic effect on your cat's health and happiness. If your cat needs to lose weight, restrict calories by 10 percent or less. It will also help if you feed your cat more mini-meals, rather than one or two big meals. You may also want to try reduced-calorie cat food, since it will enable you to feed your cat the same volume of food while still lowering calories. Cats should lose no more than half a pound per month.
- Once your cat is about seven years old, you may need to adjust its calorie intake. Just like humans, cats also suffer from a lower metabolism as they age. So if you feed your older cat the same amount you always have, you may notice that he or she puts on weight. To prevent this, gradually reduce the calories you provide your cat to about 20-25 calories per pound of weight. If you're having trouble getting your older cat to consume enough calories, try feeding him canned cat food that has been warmed a bit in the microwave, which makes it more appetizing.
- Now that you know how many calories your cat needs, you can use the nutritional information listed on cat-food packaging to figure out how much food to provide. In general, a 6.5-ounce can of cat food has 200 calories and one cup of dry cat food has 300 calories.
