Cat Food Calculator
Daily calories and food amount by weight and activity.
How to Use the Cat Food Calculator
Enter your cat's weight in pounds and select their life stage or activity level. The calculator uses the veterinary Resting Energy Requirement (RER) formula — RER (kcal/day) = 70 × (weight in kg)^0.75 — then multiplies by a life-stage factor to give a daily calorie target. It then converts calories to grams of dry food based on typical kibble density (~4 kcal/gram).
Calorie Needs by Life Stage
Kittens (under 1 year) need approximately 2.5× RER due to rapid growth — they may require 200–300 kcal/day despite being small. Intact adult cats need about 1.4× RER; spayed/neutered adults need slightly less (1.2×) since metabolism slows after the procedure. Pregnant cats need up to 2× RER in late pregnancy, while nursing queens can need 2–6× RER depending on litter size. Senior cats (11+) often need slightly less energy but higher protein quality.
Dry vs. Wet Food Portioning
Dry kibble typically contains 300–400 kcal per 100 grams. Wet food is 70–80% water, containing only 80–100 kcal per 85g can. If you feed a mix of wet and dry food, calculate the calories from each source separately and sum them against your cat's daily target. Many cats stay better hydrated on wet food, which benefits urinary tract health — particularly for male cats prone to blockages.
Monitoring Body Condition
The best guide to whether you are feeding the right amount is your cat's body condition score (BCS). A healthy cat should have ribs you can feel but not see, a visible waist when viewed from above, and a small amount of belly fat. If ribs are hard to feel or the belly droops, reduce portions by 10–15% and reassess in 4 weeks. If ribs are very prominent, increase by 10%. Weigh your cat monthly on a scale — small cats can mask significant weight changes visually.
Common Uses
- Setting precise daily dry food portions in grams and ounces
- Preventing feline obesity, the most common preventable cat health problem
- Adjusting food intake during pregnancy, nursing, or illness
- Comparing calorie needs across life stages and activity levels
Frequently Asked Questions
How much should I feed my cat?
Amount depends on weight, age, and activity. This calculator estimates dry kibble grams per day using veterinary RER formulas. Wet food quantities differ.
Should I free-feed my cat?
Most vets recommend scheduled meals rather than free-feeding, especially for indoor cats prone to obesity.
Is this tool free?
Yes, completely free.