About the Punnett Square Calculator
Build monohybrid and dihybrid crosses with the full offspring grid and ratios.
What it is
A Punnett square predicts the genotypes and phenotypes of offspring from a genetic cross by laying out every combination of parental gametes in a grid. This tool generates that grid automatically for both single-gene (monohybrid) and two-gene (dihybrid) crosses, using standard complete-dominance rules.
Features
Monohybrid & dihybrid crosses
2ร2 grids for one gene, or 4ร4 grids for two genes with independent assortment.
Automatic gamete generation
Every possible gamete combination is generated from each parent's genotype.
Genotype & phenotype ratios
Simplified ratios with percentages for both genotype and phenotype outcomes.
Custom trait labels
Name each gene's dominant and recessive phenotype for readable results.