Petfoodia

Senior dog food calculator

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

How to use the calculator

  1. Weigh your dog 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

512

kcal per day

≈ 1.46 cups

per day, split across meals

Weight
9.1 kg
Resting energy (RER)
366 kcal
Multiplier
×1.4

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 dog 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 dogs often need fewer calories

As dogs age they usually move less, lose muscle mass and their metabolism slows, so the energy they burn at rest and during the day drops. Feeding the same amount as in adulthood often leads to gradual weight gain, which puts extra strain on aging joints. That's why senior multipliers (×1.2–1.4) are lower than typical adult factors (×1.6–1.8). Some seniors instead lose weight or muscle — if your dog is gaining or losing unexpectedly, talk to your vet rather than just changing portions.

How the formula works

First we estimate the Resting Energy Requirement (RER): the calories your dog 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 20 lb senior dog with low activity

  • Weight: 20 lb ÷ 2.20462 = 9.1 kg
  • RER: 70 × 9.10.75 ≈ 366 kcal/day
  • DER: 366 × 1.2 ≈ 439 kcal/day
  • Cups: 439 ÷ 350 kcal/cup ≈ 1.25 cups/day

Example: a 45 lb senior dog with normal activity

  • Weight: 45 lb ÷ 2.20462 = 20.4 kg
  • RER: 70 × 20.40.75 ≈ 672 kcal/day
  • DER: 672 × 1.4 ≈ 941 kcal/day
  • Cups: 941 ÷ 350 kcal/cup ≈ 2.69 cups/day

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