Frequently Asked Questions
Everything you need to know about the Punnett Square Calculator.
How does the Punnett square calculator work?
Enter both parents' genotypes, choose monohybrid or dihybrid, and it builds the full offspring grid along with genotype and phenotype ratios.
What's the difference between monohybrid and dihybrid?
Monohybrid tracks one gene (a 2ร2 grid); dihybrid tracks two genes at once (a 4ร4 grid) assuming independent assortment.
Can I name the traits myself?
Yes, enter your own dominant/recessive trait labels (e.g. Purple flower / White flower) and they'll appear in the phenotype ratio.
What dominance model does it use?
Simple complete dominance by default: any genotype with at least one dominant allele shows the dominant phenotype.
What if I enter an invalid genotype?
Genotypes with the wrong number of alleles or inconsistent letters are flagged immediately with a clear message.
Does it show percentages as well as ratios?
Yes, both the raw ratio (e.g. 3:1) and the percentage breakdown are shown.
Can it handle a testcross (e.g. Aa ร aa)?
Yes, any valid combination of parent genotypes works, including testcrosses.
Is this tool free?
Completely free, no sign-up or downloads.
Is my data stored?
No; everything is calculated locally in your browser.
Does it work on mobile?
Yes, the grid is fully responsive and readable on small screens.