Pet Sums
Free dog and cat calculators built on published veterinary formulas: dog and cat age in human years, puppy adult weight, daily calories and cups of food, pregnancy due dates, and chocolate toxicity -- with the working shown.
Most pet calculators give you a number and no reason to believe it. Every tool here uses a published veterinary formula, shows the arithmetic, and explains what to do with the result -- how many cups that is, which day to call the vet, what "senior" means for a Great Dane versus a Chihuahua.
Dogs and cats get age, calorie and feeding tools built on the same resting-energy equation vets use. The emergencies section is for the moment you find the empty wrapper: it tells you whether the amount is a problem and who to call.
Dogs
Convert your dog's age to human years two ways: the 2020 UCSD epigenetic formula and the size-adjusted veterinary chart -- and see why 'multiply by 7' is wrong.
Puppy adult weightEstimate how big your puppy will get from its current weight and age in weeks, with the size-specific growth curve small, medium, large and giant breeds actually follow.
Dog calories & cups per dayHow many calories and cups of food your dog needs per day, from the veterinary RER formula (70 x kg^0.75) and the life-stage factor, using the kcal per cup on your bag.
Dog due dateYour dog's due date from the breeding date (63 days, with the 58-68 day range), plus the week-by-week milestones vets use: heartbeat, palpation, X-ray count, whelping prep.
Cats
Convert your cat's age to human years with the standard veterinary chart (15 for the first year, 24 by two, four per year after) and see which life stage your cat is in.
Cat calories per dayHow many calories your cat needs per day from the veterinary RER formula and a life-stage factor, converted into grams of dry food or cans of wet food from your label.
Emergencies
Frequently Asked Questions
Where do the formulas come from?
Each calculator names its source on the page: the 2020 UCSD epigenetic dog-age study, the veterinary RER equation (70 × kg^0.75) and WSAVA life-stage factors for calories, the Merck Veterinary Manual for theobromine thresholds and gestation milestones, and the AAFP/ISFM feline life stages. Nothing here is invented; the working is shown so you can check it.
Is this veterinary advice?
No. These are the same rules of thumb and formulas vets use as starting points, and they are a good way to sanity-check a feeding amount or a due date. They cannot see your animal. Anything involving a sick pet, a possible poisoning, or a pregnancy belongs with your vet, and the pages say so.
Do I need an account, and is anything saved?
No account, nothing saved. Every calculation runs in your browser and nothing you type is sent anywhere.