What our calculator is
PetKcal applies standard veterinary nutrition formulas — specifically the Resting Metabolic Rate (RMR) formula and lifestyle multipliers endorsed by AAFCO, NRC, and FEDIAF — to estimate daily calorie and portion requirements for common pet species. For reptiles and fish, we apply species-appropriate percentage-of-body-weight models used in herpetology and aquaculture.
These formulas are the same tools used as starting points by veterinary nutritionists in clinical practice. However, they are starting points — not final prescriptions.
What our calculator is not
- It is not a substitute for a veterinary nutritional consultation
- It is not appropriate as a sole guide for pets with diagnosed conditions (kidney disease, diabetes, cancer, pancreatitis, hyperthyroidism, heart disease, or post-surgical recovery)
- It is not guaranteed to be accurate for every breed, individual, or life situation
- It does not account for treats, table scraps, or food fed by other household members
How to use our results responsibly
Use the portion size as your starting amount. Over 4–6 weeks, monitor your pet's body condition:
- If your pet is gaining unwanted weight → reduce by 10–15%
- If your pet is losing weight unintentionally → increase by 10–15% and consult your vet
- For puppies, kittens, and growing reptiles → recalculate monthly
The goal is to use our calculator to get in the right ballpark, then fine-tune based on your individual pet's response.
Emergency situations
If your pet is showing signs of illness, extreme weight loss, refusal to eat for more than 48 hours (dogs/cats), or any abnormal behaviour — contact your veterinarian immediately. Do not attempt to resolve a medical situation with a nutrition calculator.