Biology

Dihybrid Cross (Punnett Square) Calculator

Instantly build a 4×4 Punnett square for two traits, see genotype and phenotype probabilities with this interactive dihybrid cross calculator.

Dog Pregnancy (Due Date) Calculator

Use our dog pregnancy due date calculator to estimate whelping day from mating, ovulation, LH surge or diestrus. See safe whelping window, days remaining and progress.

Dog Size & Adult Weight Calculator

Estimate your dog’s adult weight in kg, lb, g or oz from age and current weight. Puppy size calculator with toy, small, medium, large & giant categories.

Punnett Square Calculator

Use our Punnett Square Calculator to model a monohybrid cross, see AA/Aa/aa probabilities, genotypic & phenotypic ratios, and download a PDF of the results.

Percent Yield Calculator

Calculate percent yield from actual and theoretical yields. Real-time updates, unit options, step-by-step derivation, and PDF export. Free online tool.

Cat Age Calculator

Convert cat years to human years (and back). Use our Cat Age Calculator with piecewise method, quick chart, and downloadable PDF.

Benadryl Dosage Calculator for Dogs

Calculate Benadryl (diphenhydramine) dose for dogs by weight. See mg, mL, tablet/chew counts and 8–12h frequency. Educational tool—not veterinary advice.