General · Pets
Dog & cat daily calorie calculator.
Estimate how many calories a day your dog or cat needs, using the veterinary equation RER = 70 × kg0.75 and the AAHA life-stage factors.
Inputs
Result
Fill the form and press Calculate calories.
How the calculation works
Step 1 is the resting energy requirement: RER = 70 × body weight (kg)0.75. Step 2 multiplies it by a life-stage factor to get the maintenance energy requirement (MER), the daily calories to feed. Both steps come from Box 1 of the 2021 AAHA Nutrition and Weight Management Guidelines. AAHA's own example: a 10 lb (4.5 kg) neutered cat has an RER of 216 kcal and, at a factor of 1.2, an MER of 259 kcal.
Where AAHA gives a range, this tool shows the whole range and its midpoint. Start near the midpoint, weigh your pet every couple of weeks, and adjust. AAHA notes that sedentary and indoor pets may need fewer calories than the factors suggest, and that adjustments should be guided by body weight and body condition score.
Life-stage factors (MER = RER × factor)
| Stage | Cat | Dog |
|---|---|---|
| Neutered adult | 1.2–1.4 | 1.4–1.6 |
| Intact adult | 1.4–1.6 | 1.6–1.8 |
| Inactive / obese-prone | 1.0 | 1.0–1.2 |
| Weight loss | 0.8 | 1.0 |
| Gestation | 1.6–2.0 | 3.0 (last 21 days) |
| Lactation | 2.0–6.0 | 3.0–6.0 |
| Growth | 2.5 | 3.0 under 4 months; 2.0 from 4 months |
| Work | not given | light 1.6–2.0; moderate 2.0–5.0; heavy 5.0–11.0 |
Read this before you change a diet
This is an estimate for healthy animals, not veterinary advice. For weight loss, AAHA says to base the calculation on ideal weight, not current weight. Pets with illness, and pets that are underweight, obese or nursing large litters, should have a plan from a veterinarian. Lactation needs depend on litter size and week of lactation, which is why the range is wide. Also count treats: AAHA advises keeping them to 10% or less of daily calories.
Sources, and when they were checked
The equation and every factor above were read directly from the source below on 29 September 2026.
- American Animal Hospital Association — 2021 AAHA Nutrition and Weight Management Guidelines for Dogs and Cats (JAAHA 57:3), Box 1 — RER equation and life-stage factors
- AAHA — Feeding plans for healthy, appropriate-weight cats and dogs — the same guideline's web version