Enter the parents' genotypes (e.g. Aa × Aa, or AaBb × AaBb) to generate the Punnett square grid plus offspring genotype and phenotype ratios with counts, fractions and probabilities.
Examples
Enter each parent's genotype using two letters per gene (e.g. Aa for one gene, AaBb for two) and click Calculate. The tool enumerates every gamete, draws the Punnett square, and reports offspring genotype and phenotype ratios with counts, simplified fractions and percentages. Uppercase letters are dominant alleles, lowercase are recessive. Classic example: Aa × Aa → 1 AA : 2 Aa : 1 aa (genotypes) and 3 dominant : 1 recessive (phenotypes).