Vet-informed · Dogs, cats, fish & reptiles

Pet Care Calculators

The everyday questions, answered with real veterinary math — how old is my pet really, how big will the puppy get, how much should I feed, is this an emergency, what does a year of this cost. Free, instant, and private.

Dogs & Cats

Age, growth, feeding, water, toxicity and what a year of ownership actually costs.

Dog Age Calculator

Convert dog years to human years by breed and size — the accurate way, not "times seven."

Convert dog age →

Cat Age Calculator

Convert your cat’s age to human years and see its life stage and breed life expectancy.

Convert cat age →

Puppy Weight Calculator

Project how big your puppy will get, using growth curves that differ by size class.

Project adult weight →

Dog Food Calculator

How much to feed your dog, in calories and cups, based on weight and life stage.

Portion food →

Cat Food Calculator

Portion your cat’s meals to the right daily calories for its weight and age.

Portion food →

Water Intake Calculator

How much your pet should drink, and whether what you are seeing crosses the vet threshold.

Check water needs →

Chocolate Toxicity Calculator

Dog ate chocolate? Gauge the danger by weight and type, with emergency vet numbers.

Check the risk →

Xylitol Toxicity Calculator

Sugar-free gum or peanut butter? Xylitol acts within minutes — check the dose fast.

Check the risk →

Grape & Raisin Calculator

Compare what your dog ate against the lowest doses ever documented to harm kidneys.

Check the risk →

Onion & Garlic Calculator

Onion, garlic, leek or powder — convert to an onion-equivalent dose for dogs and cats.

Check the risk →

Pet Cost Calculator

What a dog or cat really costs per year — food, vet, dental, grooming, boarding, insurance.

Build the budget →

Pet Insurance Calculator

Estimate monthly premiums for dogs and cats by age, size, and state.

Estimate premium →

Aquarium

Freshwater and reef — volume, weight, stocking, heating, substrate, water changes and salt mix. All aquarium tools

Aquarium Volume Calculator

Gallons and litres from your tank’s dimensions — and the real water volume once substrate takes its share.

Work out volume →

Tank Weight Calculator

What a filled tank weighs, and whether your floor should be carrying it.

Check the weight →

Fish Stocking Calculator

How many of a species your tank actually supports — and why one inch per gallon fails.

Check stocking →

Heater Size Calculator

Wattage for your tank, adjusted for how cold the room actually gets.

Size a heater →

Substrate Calculator

Pounds of gravel, sand or aquasoil for the depth you want.

Calculate substrate →

Water Change Calculator

Change volume plus exact Prime and conditioner doses for the water you replace.

Plan a change →

Saltwater Mix Calculator

Salt mix by weight for your target salinity, plus reef parameters and top-off.

Mix saltwater →

Reptiles & Amphibians

UVB and Ferguson zones, thermal gradients, enclosure size and feeding. All reptile tools

Reptile UVB Calculator

Ferguson zone, target UV index, and how far your lamp should sit — mesh loss included.

Set up UVB →

Enclosure Size Calculator

Minimum adult enclosure by species, against what pet shops actually sell.

Check enclosure →

Reptile Heating Calculator

Basking, warm side, cool side, night and humidity targets — and how to build the gradient.

Set temperatures →

Feeder Size Calculator

Feeder insect size and prey weight by species, plus supplementation.

Size the feeders →
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Built on veterinary formulas, not guesswork

Every tool here uses the actual science: age conversions from the size-based veterinary convention and the 2020 UCSD epigenetic study; food portions and water requirements from the RER/MER energy equations; toxicity thresholds for chocolate, xylitol, grapes, and alliums from the Merck Veterinary Manual and ASPCA Animal Poison Control case data; growth curves from published canine growth research; cost and insurance figures from ASPCA, Synchrony, and NAPHIA industry data. Where a number is an estimate, we say so — and for anything urgent, we point you to a real vet. See our methodology for sources.

When to skip the calculator and call a vet

These tools inform; they don't diagnose. If your pet ate something toxic, is behaving abnormally, or you're simply worried, call your veterinarian or a 24/7 poison line — the chocolate toxicity page lists the numbers. A phone call is always the right move when something seems wrong.

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