Petfoodia

Senior cat food calculator

Enter your senior cat's weight and activity level. We estimate resting energy (RER) from body weight and apply a senior life-stage factor. For younger cats, use the cat food calculator.

How to use the calculator

  1. Weigh your cat and enter the weight in lb or kg.
  2. Pick the age group and activity level that fit best.
  3. Enter the "kcal per cup" value from your food's label.
  4. Read the daily calories and cups, then check body condition with your vet.

Questions? See the feeding FAQ, or read common feeding mistakes.

Check your food's label for "kcal/cup". The default is only a placeholder.

Estimated daily needs

261

kcal per day

≈ 0.65 cups

per day, split across meals

Weight
4.5 kg
Resting energy (RER)
218 kcal
Multiplier
×1.2

These are estimates only — not veterinary advice.

Estimate only. Individual needs vary by up to 20–30% or more. These results are for educational purposes and are not a substitute for advice from your veterinarian. Monitor body condition and adjust with your vet. Read the disclaimer.

Just want a ballpark? See the cat feeding-by-weight guide for estimated calorie ranges at common adult weights.

Last updated: November 3, 2026 · How this is calculated

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Why senior cats often need fewer calories

Older cats typically sleep more, play less and lose some muscle mass, which lowers the energy they burn each day. Continuing kitten- or adult-sized portions can lead to slow weight gain. That's why senior multipliers (×1.1–1.2) sit at the low end of the adult range. Unplanned weight loss in a senior cat is common too and can signal a health issue — check with your vet before changing the diet on your own.

How the formula works

First we estimate the Resting Energy Requirement (RER): the calories your cat burns at rest. RER = 70 × (weight in kg)0.75. Then we multiply by a life-stage factor to get the Daily Energy Requirement (DER), which accounts for activity and neuter status. Finally, DER ÷ kcal per cup gives cups per day.

Example: a 10 lb senior cat with low activity

  • Weight: 10 lb ÷ 2.20462 = 4.5 kg
  • RER: 70 × 4.50.75 ≈ 218 kcal/day
  • DER: 218 × 1.1 ≈ 240 kcal/day
  • Cups: 240 ÷ 400 kcal/cup ≈ 0.6 cups/day

Example: a 12 lb senior cat with normal activity

  • Weight: 12 lb ÷ 2.20462 = 5.4 kg
  • RER: 70 × 5.40.75 ≈ 249 kcal/day
  • DER: 249 × 1.2 ≈ 299 kcal/day
  • Cups: 299 ÷ 400 kcal/cup ≈ 0.75 cups/day

These examples are estimates only. Real needs can differ by 20–30% or more. See the methodology for details.