Free Pet Calculators & Tools
Instant answers to the numbers pet owners actually need. No account, no email, no paywall.
Dog just ate chocolate?Check the dose for your dog's weight in ten seconds, then call your vet.- Chocolate toxicity calculatorMy dog ate chocolate — is it a dangerous dose for their weight?
- Dog pregnancy calculatorDue date, whelping window and a week-by-week timeline from the mating date.
- Dog food calculatorHow many calories and grams your dog actually needs each day.
- Cat food calculatorDaily calories for a cat, and why free-feeding goes wrong.
- Aquarium volume calculatorReal water volume, filter turnover and water change size.
- Heater wattage calculatorWhat wattage heater your tank needs, and when to use two.
- Puppy weight calculatorEstimate the adult weight of a growing puppy.
- Pet age calculatorDog and cat years done properly — not multiplied by seven.
- Litter box calculatorHow many boxes, how deep, and how much litter a month.
- Water intake calculatorHow much a dog or cat should drink a day — and when it is too much.
- Crate size calculatorWhich crate size fits your dog — home crate or airline (IATA) travel crate.
- Pet insurance calculatorWhat a quoted policy would really pay — and the vet bill where it breaks even.
- Raw dog food calculatorDaily raw portion by body weight, split into 80/10/10 meat, bone and organ.
How these tools work
Every calculator here uses a published formula, and each page names the formula it uses. The feeding calculators use the Resting Energy Requirement equation from veterinary nutrition. The aquarium tools use the volume and turnover arithmetic aquarists have used for decades. The age calculator uses the curve veterinary bodies describe, not the multiply-by-seven myth.
Nothing here is a diagnosis, and nothing replaces your vet. Where a result depends on the individual animal — which is most of them — the page says so and tells you what to check instead.