Pets Calculators & Converters

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Reference calculators for dog and cat owners and aquarium keepers. Convert your dog's age to human years using size-adjusted AAHA guidelines — not the oversimplified 7× rule. Calculate cat age equivalences from AAFP/AAHA life stage classifications. Convert pet weight between pounds, kilograms, and ounces for vet visits and food labels. Estimate aquarium volume from tank dimensions for rectangular and cylindrical tanks, and calculate how much substrate you need for any footprint and depth. All tools are reference calculators — they do not provide veterinary advice.

All Pets Tools

Dog Age Calculator — Human Years by Size

Convert your dog's age to human years by size class (toy, small, medium, large, giant). Based on AAHA Canine Life Stage Guidelines. Not veterinary advice.

Cat Age Calculator — Human Years

Convert your cat's age to human years using AAFP/AAHA Feline Life Stage Guidelines. Year 1 = 15 human years. Not veterinary advice.

Pet Weight Converter — lbs, kg, oz

Convert pet weight between pounds, kilograms, and ounces. Exact NIST factors. Useful for vet visits, diet tracking, and shipping.

Aquarium Volume Calculator — Gallons and Liters

Calculate aquarium volume in US gallons and liters from tank dimensions. Supports rectangular and cylindrical tanks in inches or centimeters.

Aquarium Substrate Calculator — How Much Gravel or Sand?

Calculate how many pounds or kilograms of gravel, sand, or planted substrate you need for any aquarium. Enter tank dimensions and desired depth.

Reference Charts

Dog Age Chart

AAHA dog age chart showing human-year equivalents by size class (toy, small, medium, large, giant) from age 1–16. Sourced from AAHA Canine Life Stage Guidelines.

Aquarium Reference Chart

Aquarium quick-reference: standard tank dimensions, substrate depth guidelines, filtration turnover rates, and common fish tank sizes in gallons and liters.