Punnett Square Maker

Enter two parent genotypes and see every possible offspring, with ratios.

Cross type

Example

Parent 1 genotype

Parent 2 genotype

How to use it

Write each parent's alleles as letters. A capital letter is the dominant allele and a lowercase letter is the recessive allele. Tt means one dominant and one recessive allele. For two genes, use a different letter for each gene, such as AaBb. The square assumes complete dominance, simple inheritance of each gene, and genes on different chromosomes. Real traits can be more complicated. This tool supports the Grade 10 lesson on Mendelian genetics.