What is the Punnett Square Generator?
Generate printable Punnett squares for monohybrid and dihybrid Mendelian crosses. Add custom parent labels and trait names, choose genotype or phenotype display, and get genotype and phenotype ratios. Free, private, and runs instantly in your browser.
How to use the Punnett Square Generator
- Choose cross type and enter both parent genotypes.
- Optionally label parents and name dominant/recessive traits.
- Pick whether cells show genotype, phenotype, or both.
- Review the color-coded Punnett square and gamete lists.
- Copy the square for worksheets, slides, or study notes.
Common use cases
- Creating a labeled Punnett square for a biology worksheet
- Visualizing a pea plant dihybrid cross with trait names
- Generating a test-cross square for yyrr × YyRr
Frequently asked questions
- How do I label traits on the Punnett square?
- Enter dominant and recessive trait names for each gene (e.g. Purple / White for flower color). Leave blank to use default allele-based labels.
- What do the green and pink cell colors mean?
- Green cells show offspring with all dominant traits expressed. Pink cells indicate at least one recessive trait in the phenotype.
- What is a genotype ratio?
- The genotype ratio summarizes how many of each genotype appear in the square, reduced to simplest form (e.g. 1:2:1 for Aa × Aa).
- Can I generate a dihybrid Punnett square?
- Yes. Enter four-allele genotypes like YyRr × YyRr and add trait names for both genes.
- Is my data uploaded?
- No. The square is generated locally in your browser.
