Cat Food Calculator
Find how much to feed your cat per day.
Neutered adult ~1.2, active ~1.4
Check the bag; dry food often 300-500
Results update as you type.
How it works
Cats are prone to obesity when overfed, so measuring portions matters, and this calculator estimates daily food from veterinary energy formulas. You enter your cat's weight, an activity factor, and the calories per cup of its food, and it returns the daily calories and cups to feed. As with dogs, it starts from the resting energy requirement (RER) — 70 times the cat's weight in kilograms to the 0.75 power — then multiplies by an activity factor for the total daily need. Cats generally use lower factors than dogs: about 1.0 for weight loss, 1.2 for a typical neutered indoor adult, up to 1.4 for active cats, and higher for kittens or pregnant cats. Dividing by the food's calorie density gives the daily amount. Because many cats are indoor and sedentary, and treats add up, portion control is important to prevent weight gain, which contributes to diabetes and joint problems. This calculator often works out to a modest amount — many adult cats need only around 200 to 250 calories a day — which surprises owners who free-feed. Wet food has far fewer calories per volume than dry, so adjust the calorie-per-cup value for your food type. Monitor your cat's body condition and adjust, and consult your vet for kittens, seniors, or cats with health issues. Enter your cat's weight, activity, and food calories to estimate the portion.
RER = 70 × (kg^0.75); daily calories = RER × activity factor; cups = calories ÷ kcal per cup
A cat's resting energy requirement (RER) is 70 times its weight in kilograms to the 0.75 power. Multiplying by an activity factor gives the daily calorie need, and dividing by the calories per cup of food gives the cups to feed. Cats have lower activity factors than dogs.
Source:Veterinary energy requirements (RER/MER)
We review all our tools from time to time to ensure accuracy.
Worked example
How to use this calculator
- 1
Enter your values
Enter cat's weight.
- 2
Adjust the options
Adjust activity factor and calories per cup of food if they apply — sensible defaults are already set.
- 3
Read your result
Daily calories updates instantly as you type — no button to press.
Frequently asked questions
How much should I feed my cat?
Estimate your cat's daily calories from its weight and activity, then divide by the calories per cup of its food. A typical 10-pound indoor cat needs only about 250 calories a day, often around a cup of dry food. Many cats are overfed, so measure portions and monitor weight rather than free-feeding.
Why do cats have lower activity factors than dogs?
Cats, especially indoor ones, are generally less active than dogs and have lower energy needs relative to size. Typical cat factors are about 1.2 for a neutered adult versus 1.6 for dogs. Using the right lower factor prevents overfeeding, which is a common cause of feline obesity given how sedentary many house cats are.
How does wet food change the calculation?
Wet (canned) food has far fewer calories per volume than dry food because it is mostly water, so a cup of wet food has a fraction of the calories of a cup of dry. Use the calorie content for your specific food — often listed per can or per cup — so the portion is accurate for the food type you feed.
Why is portion control important for cats?
Overfeeding leads to weight gain, and feline obesity is common and serious, contributing to diabetes, joint problems, and a shorter lifespan. Because many cats are indoor and sedentary and treats add up quickly, free-feeding often results in overeating. Measuring meals to a calculated portion helps keep your cat at a healthy weight.
Should kittens use this calculator?
No. Kittens need far more calories per pound for growth and use higher, age-dependent multipliers, so this adult-maintenance estimate is too low for them. Pregnant and nursing cats also have elevated needs. For kittens, pregnant or nursing cats, or cats with medical conditions, follow stage-appropriate feeding guidelines or ask your veterinarian.