Punnett Square Calculator
Predict the probability of offspring genotypes based on parental alleles
🧬 Parental Genotypes
📚 Genetic Concepts
Key Terms:
- • Genotype: Genetic makeup of an organism
- • Phenotype: Observable characteristics
- • Homozygous: Two identical alleles (AA or aa)
- • Heterozygous: Two different alleles (Aa)
- • Dominant: Allele that expresses in heterozygotes
- • Recessive: Allele only expressed in homozygotes
🔍 Punnett Square Results
📊 Genotype Probabilities
🧬 What is a Punnett Square?
A Punnett Square is a diagram used in genetics to predict the probability of different genotypes in the offspring of a cross between two parents.
It was developed by Reginald Punnett and provides a visual representation of Mendelian inheritance.
⚖️ Mendelian Inheritance
Gregor Mendel’s principles form the foundation of classical genetics:
- ✓ Law of Segregation: Alleles separate during gamete formation
- ✓ Law of Independent Assortment: Genes for different traits separate independently
- ✓ Law of Dominance: Dominant alleles mask recessive alleles
🔍 Applications in Genetics
Punnett Squares are essential tools for:
- • Predicting inheritance patterns
- • Genetic counseling and risk assessment
- • Plant and animal breeding programs
- • Understanding genetic disorders
- • Educational genetics instruction
Note: Real-world genetics can be more complex with factors like incomplete dominance, codominance, and polygenic inheritance.
Punnett Square Calculator – Predict Genetic Crosses Instantly
Discover how traits are inherited with our easy-to-use Punnett Square Calculator.
Whether you’re studying basic Mendelian genetics or performing complex multi-trait crosses, this calculator helps you predict offspring genotypes, phenotypes, and probabilities in seconds.
At Smart Unit Calculator, we simplify genetics for students, teachers, and researchers. Our Punnett Square Calculator visualizes possible combinations of parental alleles, giving you a clear understanding of dominant and recessive inheritance patterns.
🧫 How to Use the Punnett Square Calculator
- Select the Type of Cross
- Monohybrid (one trait)
- Dihybrid (two traits)
- Custom (multi-trait or custom allele setup)
- Enter Parent Genotypes
- Example: Parent 1 = Aa, Parent 2 = Aa
- Choose Dominant & Recessive Alleles
- Example: A = dominant, a = recessive
- Click “Calculate”
- Instantly see all possible offspring genotypes and phenotypes
- Get genotype and phenotype ratios with percentage probabilities
- Analyze Results
- Understand how traits will likely appear in the next generation
🧮 Example: Monohybrid Cross
If both parents have genotype Aa (heterozygous), the Punnett square will show:
| A | a | |
|---|---|---|
| A | AA | Aa |
| a | Aa | aa |
- Genotypic Ratio: 1 AA : 2 Aa : 1 aa
- Phenotypic Ratio (assuming A is dominant): 3 dominant : 1 recessive
This illustrates classic Mendelian inheritance, where dominant alleles mask recessive ones in heterozygous combinations.
🔬 Why Use the Punnett Square?
- ✅ Instant Results: No manual grids or errors — get calculations in seconds.
- ✅ Supports Multiple Traits: Go beyond simple monohybrid crosses and calculate dihybrid or custom crosses.
- ✅ Educational Value: Great for teaching and learning Mendelian genetics.
- ✅ Accurate Ratios & Probabilities: Based on standard Mendelian formulas.
- ✅ Free and Easy to Use: No signup, no complexity — just reliable results.
👩🏫 Who Can Benefit from This Tool?
- Biology Students – Understand inheritance and practice Punnett square problems.
- Teachers – Demonstrate genetic crosses in real time for classroom learning.
- Geneticists & Researchers – Model inheritance patterns in controlled crosses.
- Breeders (Plants or Animals) – Predict how specific traits may appear in offspring.
- Curious Learners – Explore how genes combine to shape traits like eye color, flower color, or blood type.
🌱 Common Use Cases
- Predicting eye color inheritance in humans
- Determining flower color or seed texture in plants
- Modeling coat color inheritance in animals
- Teaching Mendelian genetics and allele combinations
- Exploring probability in genetic counseling scenarios
📊 Types of Crosses Supported
| Type | Description |
|---|---|
| Monohybrid Cross | Single trait cross (e.g., Aa × Aa) |
| Dihybrid Cross | Two traits (e.g., AaBb × AaBb) |
| Trihybrid or Custom | Three or more traits for advanced genetics students |
Each type automatically generates genotype and phenotype ratios, helping you visualize inheritance complexity.
💡 Key Genetics Concepts Explained
- Genotype: The genetic makeup (e.g., Aa or BB).
- Phenotype: The visible or expressed trait (e.g., brown eyes, yellow seeds).
- Dominant Allele: Expressed even if only one copy is present.
- Recessive Allele: Expressed only when two copies are present.
- Homozygous: Two identical alleles (AA or aa).
- Heterozygous: Two different alleles (Aa).
Understanding these basics helps interpret Punnett square results accurately.
Stop guessing — predict inheritance the smart way.
Our Punnett Square Calculator combines biology, probability, and precision to deliver clear, fast, and educational results for any genetic cross.