Free pet calculators, with the maths shown

15 quick tools for dogs, cats, fish, reptiles, birds and small pets: age in human years, puppy adult weight, daily and raw food, crate and harness size, tank volume, cage size, pregnancy due dates and pet insurance payouts. Every number comes from published veterinary or welfare guidance, linked on the page.

DogsCatsFishReptilesBirdsSmall pets

Dogs

Dog age calculatorDog years to human years, by size.Puppy weight calculatorHow big will my puppy get?Dog food calculatorCalories and cups a day, from your food’s label.Crate, collar, harness & bed sizeOne tape measure, four sizes.Raw dog food calculatorGrams a day by weight, age and activity.

Cats

Cat age calculatorCat years to human years and life stage.Cat food calculatorCalories and cups a day, from the label.Litter box calculatorHow many boxes, and how big.

Fish, reptiles, birds & small pets

Aquarium calculatorGallons, litres, weight, heater and filter.Reptile tank sizeMinimum enclosure by species, and a check of yours.Cage size calculatorHamsters to macaws, plus coop space for chickens.Pet name generatorIdeas for dogs, cats, fish, birds, reptiles and small pets.

Pregnancy & insurance

Dog pregnancy calculatorDue date and timeline from the mating date.Cat pregnancy calculatorWhen the kittens are due, week by week.Pet insurance payout calculatorWhat a policy pays on a vet bill, and break-even.

Quick answers

Quick answers
Question	Answer
How old is a 7-year-old dog in human years?	About 47 (medium dog)	Dog age
How old is a 10-year-old cat in human years?	About 56	Cat age
How much should a 50 lb dog eat?	About 1,164 kcal a day (neutered adult)	Dog food
How many litter boxes for 2 cats?	3: one per cat, plus one	Litter boxes
What size tank for a bearded dragon?	At least 4 × 2 × 2 ft	Answer
How many gallons is a 48 × 13 × 21 in tank?	56.7 gallons	Aquarium

All answers →

How we keep it honest

Figures come from sources such as the Pet Nutrition Alliance, AAHA/AAFP, MSPCA and the Merck Veterinary Manual, linked on every page.
Where a rule is only a rule of thumb, the page says so.
No symptom, toxicity or medicine tools: that’s your vet’s job.
Your entries never leave your browser.

Save to Pinterest · Download the pin image