Cat Food Calculator
Cats Are Not Small Dogs, and Their Feeding Math Isn't Either
Cats have a lower resting energy multiplier than dogs at almost every comparable life stage — a neutered adult cat's maintenance factor (1.2) is noticeably below a neutered adult dog's (1.6), reflecting differences in typical activity level and metabolism between the species. Applying a dog-oriented feeding rule to a cat, or eyeballing a bag's chart, routinely over- or under-feeds. This calculator uses the cat-specific multiplier set to size a daily ration from actual body weight.
The Formula
MER (kcal/day) = RER × Life-Stage Factor
Cups/day = MER ÷ Calories per Cup of Food
Weight entered in pounds converts to kilograms (÷ 2.20462) before the RER calculation. The life-stage factor ranges from 1.0 for weight loss up to 2.5 for kittens, which are still growing and burn substantially more energy per pound of body weight than an adult cat.
Scenarios Where This Matters
- Indoor weight management — indoor cats are prone to overfeeding since their activity level rarely matches the "neutered adult" default; the weight-loss factor gives a defensible lower target when a vet recommends a diet.
- Kitten growth — the kitten multiplier (2.5) is more than double the neutered-adult figure, reflecting how much energy growth itself consumes in the first year.
- Comparing foods — wet and dry foods differ enormously in calorie density; entering the actual kcal/cup (or kcal-equivalent) for your food keeps the cups/day figure meaningful.
| Weight (lb) | RER (kcal/day) | Neutered adult (1.2×) cups/day | Kitten (2.5×) cups/day |
|---|---|---|---|
| 5 | 129 | 0.5 | 1.1 |
| 8 | 184 | 0.7 | 1.5 |
| 10 | 218 | 0.9 | 1.8 |
| 12 | 249 | 1.0 | 2.1 |
| 15 | 295 | 1.2 | 2.5 |
RER = 70 × (weight in kg)0.75; cups/day rounded to one decimal.
How to Use This Calculator
- Enter the cat's weight in pounds.
- Select the life stage / activity level — neutered adult, intact adult, weight loss, weight gain, or kitten.
- Optionally enter the calories per cup for your specific food (defaults to 300 kcal/cup if left blank).
- Select Calculate to see the estimated daily calorie need and cups of food per day.
Related Calculations
Check the Pet Age Calculator to confirm your cat's life stage, or see the Dog Food Calculator for a multi-pet household.