Pet Calculators
Free, verified pet calculators with step-by-step guides and reference data.
Aquarium Substrate Calculator — Sand, Gravel & Aqua Soil Pounds
Calculate how many pounds of sand, gravel, or aqua soil your tank needs from length, width, depth, and density. Presets for common tank sizes.
Dog Food Calculator — Daily Portion by Weight & Life Stage
Calculate your dog's daily food portion in cups or grams using the veterinary RER/DER formula, weight, and life-stage activity level.
Horse Color Calculator — Coat Color Genetics Predictor
Predict horse coat color from genotype: base color, cream, dun, champagne, silver, grey, roan, and spotting patterns, with the Frame Overo lethal warning.
Animal Gestation Calculator — Dog, Cat, Cattle, Goat, Horse
Estimate a due date for dogs, cats, cattle, goats, or horses from the breeding date. Species-specific earliest/expected/latest gestation windows.
Chocolate Toxicity Calculator for Dogs
Estimate theobromine toxicity risk after your dog eats chocolate, by weight and chocolate type. Includes ASPCA Poison Control guidance.
Dog Age Calculator — Human Years by Breed Size
Convert your dog's age to human years using the AVMA breed-size method or the UCSD epigenetic DNA formula. More accurate than the outdated x7 rule.
Puppy Weight Calculator — Predict Adult Dog Weight
Predict your puppy's adult weight from current age and weight using size-category growth curves for toy, medium, large, and giant breeds.
Cat Coat Color Calculator: Kitten Genetics Predictor (Punnett Square)
Predict kitten coat colors from parent genetics using Punnett squares. Covers B, D, O, and A loci — black, chocolate, cinnamon, dilutes, and tortoiseshell.
Fish Tank Stocking Calculator: Inch-per-Gallon, Surface Area & Bioload
Calculate how many fish your aquarium can hold using 3 methods: inch-per-gallon, surface area, and bioload. Fresh and saltwater. 13 preset species.