About PawReckon

PawReckon is a set of free pet-care calculators for dogs, cats, fish and small pets: age, food portions, aquarium volume and stocking. Everything runs in your browser: there's no account, and the pets you save (in My Pets) are stored only on your device and never sent anywhere.

How the numbers are made

The age calculator uses a breed-size-adjusted method rather than the debunked "×7" rule. The food calculator uses the standard veterinary-nutrition RER/MER formula (resting energy requirement × a life-stage factor). The aquarium tools use standard tank geometry and a bioload-based stocking estimate instead of the oversimplified "one inch per gallon" rule.

Not a substitute for your vet

The feeding tools give general estimates only. Your pet's real needs depend on their health, body condition and metabolism, so always confirm with your veterinarian.