A Punnett Square calculator is an interactive tool that uses Mendelian principles to predict the possible genetic outcomes of a cross or breeding experiment. Named after British geneticist Reginald C. Punnett (1905), the Punnett Square visually shows how traits may be inherited from parents to offspring, helping you understand heredity probabilities at a glance.

To use it, simply enter the genotypes (the genetic makeup of each parent, e.g., dominant “A” vs. recessive “a”) into the calculator. The tool automatically builds the Punnett Square by combining parental alleles to display every possible genotype and phenotype your offspring could inherit.

Our goal is to make genetics learning interactive, simple, and accessible with accurate, science-based tools you can use anytime for free.

🔬 Accurate Genetic Predictions

Get fast, reliable results for genotypes and phenotypes based on parental alleles. Perfect for students, teachers, and researchers who need accurate inheritance probabilities instantly.

🧬 Covers Multiple Trait Types

From monohybrid and dihybrid crosses to more complex genetic scenarios, our calculator supports multiple inheritance patterns in one place.

⚡ Quick & Easy to Use

No complicated formulas or charts! Simply enter the parent genotypes and click “Calculate” to generate your Punnett Square instantly.

🎓 Free Educational Tool

Completely free to use — ideal for classrooms, science projects, and self-learning about Mendelian genetics. Learn how traits are passed on without cost or sign-up.

FAQs – Punnett Square Calculator

1. What is a Punnett Square and how does this calculator help?

A Punnett Square is a tool used to predict the possible genotypes and phenotypes of offspring from a genetic cross. Our calculator lets you quickly visualize the inheritance of traits using alleles from both parents.

2. How do I enter alleles for a genetic cross?

Simply input the alleles of each parent (e.g., AA, Aa, or aa). The calculator will automatically generate all possible offspring genotypes and their corresponding phenotypes.

3. Can this calculator handle multiple traits?

Yes! You can perform monohybrid, dihybrid, trihybrid, tetrahybrid, and even pentahybrid crosses to see inheritance patterns for one to five traits simultaneously.

4. What do genotype and phenotype results mean?

• Genotype: The genetic makeup of offspring (e.g., AA, Aa, or aa).

• Phenotype: The observable traits, such as eye color or flower color, resulting from the genotype.

5. What if I don’t know dominant or recessive traits?

No problem! Our calculator assumes standard dominant/recessive patterns, but you can also customize traits if you know specific dominance relationships to get accurate predictions.