Result

Genotypes

AaBb 4/16 · AABb 2/16 · AaBB 2/16 · Aabb 2/16 · aaBb 2/16 · AABB 1/16 · AAbb 1/16 · aaBB 1/16 · aabb 1/16

dominant A, dominant B

9 / 16

56.25%

dominant A, recessive b

3 / 16

18.75%

recessive a, dominant B

3 / 16

18.75%

recessive a, recessive b

1 / 16

6.25%

Phenotypes assume complete dominance (capital letter = dominant allele) and genes that assort independently.

Punnett square

	AB	Ab	aB	ab
AB	AABB	AABb	AaBB	AaBb
Ab	AABb	AAbb	AaBb	Aabb
aB	AaBB	AaBb	aaBB	aaBb
ab	AaBb	Aabb	aaBb	aabb

How to use the Punnett Square Calculator

Enter each parent's genotype, e.g. Aa or AaBb.
Read the Punnett square.
Check the genotype and phenotype ratios.

What does this tool do?

A Punnett square shows all the ways parents' alleles can combine. Each parent passes one allele of each gene to every offspring.

A classic dihybrid cross AaBb × AaBb gives the 9 : 3 : 3 : 1 phenotype ratio. Capital letters are dominant alleles and lowercase are recessive.

Why use it?

Up to three genes.
Genotype and phenotype ratios.
Full square shown.

Accuracy and limits

Assumes complete dominance and independent assortment (genes on different chromosomes).

Privacy

The calculation happens instantly in your browser. The numbers you enter are not sent to our servers or saved. There's no account to create and nothing to install.

Last reviewed October 4, 2026 by the M2Toolkit team.