How the Cat Food Calculator Works
This cat food calculator tells you how much to feed your cat in real portions — cups of dry, cans of wet, or grams — not just a calorie number. It first finds your cat’s daily calories with the vet formula (RER = 70 × weight in kg0.75, then × an activity factor of about 1.2 for a neutered indoor adult), then divides by your food’s calorie density from the label. A healthy 10 lb (4.5 kg) indoor cat needs about 200–250 calories a day — roughly ½ cup of dry food or 2–2.5 small (3 oz) cans of wet, or a mix of both. Because kibble is far more calorie-dense than canned food, portion sizes change a lot by diet type, which is why you always check the kcal per cup or can.
The five tools cover how much to feed, a quick feed-by-weight answer, a weight-loss portion, a grams-and-cost converter, and a kitten mode.
Cat Feeding Chart (How Much to Feed by Weight)
This feeding chart shows typical daily food for a neutered indoor adult cat at each weight, at common calorie densities. Use it as a starting point, then adjust to your cat’s weight.
| Cat weight |
Calories/day |
Dry food (~400 kcal/cup) |
Wet food (~100 kcal/can) |
| 5 lb (2.3 kg) |
~155 kcal |
~1/3 cup |
~1.5 cans |
| 8 lb (3.6 kg) |
~220 kcal |
~1/2 cup |
~2 cans |
| 10 lb (4.5 kg) |
~260 kcal |
~1/2–2/3 cup |
~2.5 cans |
| 12 lb (5.4 kg) |
~295 kcal |
~2/3 cup |
~2.5–3 cans |
| 15 lb (6.8 kg) |
~350 kcal |
~3/4–1 cup |
~3–3.5 cans |
These amounts assume typical calorie densities — your food will differ, so read the label and use the calculator above. Feed to your cat’s healthy target weight, not an overweight current weight.
How Much Wet and Dry Food Should I Feed?
For mixed feeding, pick a calorie split — 50/50 is common — and feed half the daily calories from each. For a 10 lb cat on about 240 calories, that is roughly a quarter cup of dry plus one to one-and-a-quarter 3 oz cans of wet a day. The key is that wet and dry are not interchangeable by volume: a cup of kibble can carry three to five times the calories of a can of wet food. Many vets like a wet-leaning or mixed diet because the extra moisture supports urinary and kidney health and helps cats feel full on fewer calories. Whatever the mix, the daily calories must add up to the target — the How Much to Feed tab does the split for you.
Is One Cup of Dry Cat Food a Day Too Much?
For most cats, yes — a full cup of dry food a day is usually too much. A cup of kibble is often 350–500 calories, while a typical 10 lb indoor cat only needs around 200–250 calories total. So most adult cats eat closer to a third to a half cup of dry food a day, or less if they also get wet food. A full cup suits only a large or very active cat, or a growing kitten. This is exactly why package guidelines and free-feeding a full bowl lead to weight gain — measure the portion to the calorie target instead.
How to Work Out the Calories in Your Cat Food
The calorie density is on the label as metabolisable energy (ME), usually written as kcal per cup, kcal per can, or kcal per kg. To go from kcal/kg to kcal/100 g, divide by 10. If only the guaranteed analysis is printed, you can estimate with the standard values of about 4 calories per gram of protein and carbohydrate and 9 per gram of fat, though the printed ME is more reliable. Once you know the density, the Grams & Cost tab converts your calorie target into grams a day — the most precise way to portion — and can estimate your monthly food cost too.
Frequently Asked Questions
How do I calculate how much food to feed my cat?
Work out the daily calories (RER × activity factor), read the kcal per cup or per can on the food label, and divide the calories by that density to get the portion. The calculator above does all three steps and splits wet and dry for you.
How much should I feed my cat by weight?
A neutered indoor cat needs roughly 20 calories per pound of ideal weight — about 200 kcal for a 10 lb cat, which is near half a cup of dry food or 2 to 2.5 small cans of wet a day. Use the By Weight tab for your cat’s exact figure.
Is 1 cup of cat food a day too much?
For most cats, yes. A cup of dry food is often 350 to 500 calories, while a 10 lb indoor cat needs only about 200 to 250. Most adult cats eat a third to a half cup of dry food a day, less if they also get wet food.
How much wet and dry food should I feed together?
Choose a calorie split (50/50 is common) and feed half the daily calories from each. Remember wet and dry are not equal by volume — match the calories, not the cups. The How Much to Feed tab calculates the mixed portion.
How much should I feed my cat to lose weight?
Feed about 80% of the RER for the target weight, aiming to lose only 0.5 to 1% of body weight per week. Never crash-diet a cat, as rapid loss can cause hepatic lipidosis. The Weight Loss tab gives the portion in cups and cans.
How do I work out the kcal in cat food?
Look for the metabolisable energy (ME) on the label in kcal per cup, per can or per kg. Divide kcal/kg by 10 for kcal per 100 g. If it is missing, estimate with 4 kcal per gram of protein and carbohydrate and 9 per gram of fat.
How much should I feed a kitten?
Kittens need 2 to 2.5 times their RER, far more per kilo than adults, spread over several small meals of a food labelled for growth. The Kitten tab converts that into cups or cans of kitten food by age and weight.
Should I measure cat food in cups or grams?
Grams, on a kitchen scale, is far more accurate. Measuring cups routinely over-pour and are a leading cause of feline obesity. The Grams & Cost tab converts your calorie target into grams a day.
More Cat & Pet Calculators
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PetCalculatorHub Editorial Team
Portions here are built from the veterinary RER formula (70 × kg^0.75) and MER activity factors, then converted using typical calorie densities you can override from your own food label. These are starting estimates — calorie density varies by brand, so read the label, weigh in grams, track your cat’s weight, and ask your vet before a weight-loss diet or for a cat with a health condition.
Last updated: October 2026
