Science Calculators
Calculators for biology and genetics homework. The Punnett Square Calculator predicts the genotypes and phenotypes of a genetic cross.
1 calculator each one also works as a widget
What the Punnett Square Calculator Covers
It builds the square for one, two or three genes (2 × 2, 4 × 4 and 8 × 8 grids), for a gene on the X chromosome, and for ABO blood types. Each gene can follow complete dominance, incomplete dominance or codominance, and you can name the traits, such as purple and white flowers.
The result gives the phenotype ratio, the genotype ratio and the chance of each outcome, with the working. The classic answers come straight out: 3 : 1 for Aa × Aa and 9 : 3 : 3 : 1 for AaBb × AaBb.
Frequently Asked Questions
What does a Punnett square show?
Every way two parents can pass on their alleles. Each square is one equally likely child, so counting squares gives the chance of each genotype and phenotype.
Can the calculator do blood types?
Yes. Switch to Blood type and pick each parent's type and genotype, for example A (IAi) and B (IBi). It shows the chance of each blood type for a child.
Are the science calculators free?
Yes. They are free and run in your browser, with nothing to download and no account to create.