The directions for the tool are at the bottom of the page.

Here they are also.

Punnett Square (P-Square) Calculator

Punnett square is a chart used by geneticists to show all possible allelic combinations of gametes in a cross of parents with known genotypes. Predicted offspring genotype frequencies can be calculated by tallying the allelic combinations in the P-square.

This online calculator draws Punnett squares and calculates offspring genotype frequencies. Punnett squares can be easily generated for monohybrid, dihybrid, or trihybrid crosses. To use the calculator, simply select parental genotypes from the pull down menu or input your own genotypes.

Input genotypes should be in the following format:



An allele is represented by a single letter (e.g. G or g. Hg will be treated as two alleles, i.e., H/g).

Inputs are case-sensitive, i.e., G and g are two different alleles.