Cat Food Calculator
Calculate your cat's daily calorie needs, cups of dry food, and cans of wet food based on weight, age, activity level, and spay/neuter status.
Quick Answer
An average 10 lb indoor adult cat needs roughly 200-250 calories per day. That translates to about 1/2 cup of dry food or 1 can of wet food daily. Kittens need significantly more calories per pound for growth, while senior cats need fewer to avoid weight gain. Use the calculator below for your cat's exact needs.
Results
Your 10 lb adult cat (4.5 kg) has a Resting Energy Requirement (RER) of 218 kcal. With a 1.2x activity multiplier, the daily energy requirement is 261 kcal.
Feeding Guide
Daily Calorie Breakdown
Feeding Tips
- Split daily portions into 2-3 meals for adult cats
- Kittens under 6 months should eat 3-4 smaller meals
- Always provide fresh water, especially with dry food diets
- Check your specific food brand's calorie info for more accuracy
- Consult your vet if your cat needs to gain or lose weight
About This Tool
The Cat Food Calculator uses the veterinary-standard Resting Energy Requirement (RER) formula to determine how many calories your cat needs each day. Unlike the generic feeding guidelines printed on cat food bags, which are designed for an "average" cat, this calculator personalizes the recommendation based on your cat's exact weight, life stage, activity level, and whether they have been spayed or neutered.
How the RER Formula Works
The Resting Energy Requirement represents the number of calories a cat burns at rest, just to keep organs functioning, maintain body temperature, and support basic cellular processes. The formula is RER = 70 x (body weight in kg)^0.75. This allometric scaling formula accounts for the fact that smaller animals have higher metabolic rates relative to their body weight. A 4 kg cat does not need exactly twice the calories of a 2 kg cat; the relationship is non-linear. The 0.75 exponent, known as Kleiber's law, has been validated across hundreds of animal species and is the gold standard in veterinary nutrition.
Understanding Calorie Multipliers
The RER gives you a baseline, but your cat's actual calorie needs depend on several factors. Intact (not spayed/neutered) cats have higher metabolic rates driven by reproductive hormones, so they need roughly 10-20% more calories than fixed cats. Outdoor cats burn significantly more energy through physical activity, thermoregulation in varying temperatures, and the mental stimulation of exploring. Indoor cats, on the other hand, tend to be more sedentary, and overfeeding them is the leading cause of feline obesity. Kittens require the highest multiplier at 2.5x RER because they are growing rapidly, building muscle and bone at an extraordinary rate during their first year of life. Senior cats need fewer calories as their metabolism slows, but protein quality becomes even more important to maintain muscle mass.
Dry Food vs. Wet Food
This calculator provides portions for both dry kibble (averaging 400 kcal per cup) and wet food (averaging 250 kcal per standard 5.5-ounce can). Many veterinarians recommend a combination of both. Dry food is convenient and helps with dental health through mechanical abrasion, though this benefit is debated. Wet food provides crucial hydration since cats have a naturally low thirst drive, an evolutionary trait from their desert-dwelling ancestors. Cats fed exclusively dry food often exist in a state of mild chronic dehydration, which can stress the kidneys over time. A mixed feeding approach, sometimes called "combo feeding," gives your cat the benefits of both types while adding variety to their diet.
Signs of Proper Nutrition
A well-fed cat should have a visible waist when viewed from above, and you should be able to feel (but not prominently see) their ribs. Their coat should be glossy and smooth, their eyes bright, and their energy levels appropriate for their age. If your cat is gaining weight despite following these calorie guidelines, they may need a veterinary evaluation to rule out underlying conditions like hypothyroidism or to adjust for a particularly sedentary lifestyle. Conversely, if your cat is losing weight while eating the recommended amount, this could indicate dental problems, parasites, diabetes, or hyperthyroidism, all of which require veterinary attention.
Common Feeding Mistakes
The most frequent mistake cat owners make is free-feeding dry food, leaving a bowl full at all times. While some cats self-regulate, many will overeat out of boredom, leading to obesity. Portion control using measured meals is far more effective for weight management. Another common error is following bag guidelines without adjustment, which tend to overestimate portions since food manufacturers have an inherent interest in you buying more food. This calculator provides an independent, science-based recommendation. Finally, many owners underestimate the calorie contribution of treats. Treats should comprise no more than 10% of daily calories, meaning a 200-calorie-per-day cat should get no more than 20 calories from treats.