Free Punnett Square Maker & Calculator

It combines the parental genotypes you choose in a 2×2, 4×4 or 8×8 square and groups the outcomes by genotype and phenotype, with ratios, fractions and percentages. Each box has probability 1/4, 1/16 or 1/64 in this model. These are conditional probabilities for the selected cross, not a guaranteed number or order of offspring.

Complete dominance, incomplete dominance, codominance, the simplified ABO blood-type model and X-linked recessive inheritance. X-linked mode is limited to Monohybrid, with Mother across the top, Father down the side and daughter/son results shown separately. These are classroom models using supplied genotypes, not a way to diagnose a condition or establish parentage.

The model gives each parental allele equal probability and assumes independent assortment for multiple genes. AaBb therefore supplies AB, Ab, aB and ab at 1/4 each. Enable Gamete list to show the combinations above the square. Identical gametes from a homozygous parent repeat in the grid; their offspring outcomes are combined in the totals. Linked genes and recombination frequencies are not modeled.

The genotype ratio counts the allele combinations; the phenotype ratio counts what the offspring look like. Aa × Aa gives a 1 : 2 : 1 genotype ratio (AA, Aa, aa) but a 3 : 1 phenotype ratio under complete dominance, because AA and Aa look the same. With incomplete dominance the heterozygote looks different, so both ratios are 1 : 2 : 1.

Choose the mother's and father's genotypes in the one-gene X-linked recessive model. For the Color blindness starter, a carrier mother and unaffected father give a 50% carrier probability among daughters and a 50% affected probability among sons. Those percentages use each sex as the denominator; they are not promises about a particular family.

Yes. Click either parent's genotype on the square, or any of that parent's gametes along the top or side, and pick a new genotype from the list that opens. It only offers genotypes that fit the gene: a father in an X-linked cross gets XᴮY or XᵇY, and blood type offers all six ABO genotypes. The list never appears in the download.

Yes. Under Style, Worksheet: blank answers removes the offspring-cell answers and ratio results. Blank the gametes too also hides the gamete answers. The parent cross, trait key and per-box probability remain as prompts. Download the worksheet, then turn Worksheet off to restore the answer key and download again.

It places the uppercase allele first in pairs such as Aa, X before Y in the X-linked model, and uses superscripts for labels such as Iᴬi and XᴮY. These are computed labels: change a parent's genotype with its picker or change the allele letters under Data rather than typing into an offspring cell.

A Start from example replaces the genes, parents, title, subtitle and trait labels and turns Worksheet off. Reducing the cross size removes the extra genes; adding them back creates defaults, not the removed edits. Changing an inheritance pattern can reset its trait labels and parent choices. Custom titles and subtitles stay when you change the cross, so check that they still describe it. Download or save work before replacing it.

Making a cross and downloading a standard PNG is free without signup or a watermark. Slide, Page and Square are starting canvas sizes; content can increase the height, so use the actual dimensions shown above the preview. A PNG is an image, not an editable saved design. Save requires sign-in; free accounts keep up to three designs. SVG and 2×, 3× and 4× HD PNG require Pro or an active export pass.