Gene Ratio Calculator
Calculate genotype and phenotype ratios from genetic crosses. Generate Punnett squares and analyze inheritance patterns for dominant and recessive traits.
Genetic Cross Setup
First parent's genetic makeup
Second parent's genetic makeup
Inheritance pattern for the trait
Genetic Analysis
Select parent genotypes and click "Calculate Gene Ratios" to see results
What Is a Gene Ratio?
A gene ratio shows how genetic traits are distributed among offspring based on parental genes. It helps explain why certain traits appear more often than others. Gene ratios are commonly taught using simple genetic crosses, especially for dominant and recessive traits.
Each parent passes one allele to their offspring. The combination of these alleles determines the genotype (gene combination) and phenotype (visible trait). By listing all possible allele combinations, we can calculate ratios and probabilities.
This calculator makes these relationships clear without manual Punnett square drawing.
How Gene Ratios Are Determined
Gene ratios are determined by systematically listing all possible combinations of alleles from both parents. This is traditionally done using a Punnett square, a grid that shows all possible genetic outcomes.
- Genotype Ratio: Shows the proportion of different gene combinations (AA, Aa, aa)
- Phenotype Ratio: Shows the proportion of different visible traits (Dominant vs Recessive)
- Allele Frequency: Shows the proportion of different alleles in the population
The calculator automates this process, making it easy to see inheritance patterns at a glance.
Formula Used in the Calculator
Genetic Probability Formulas
Probability = Favorable Outcomes ÷ Total Outcomes
Phenotype % = (Phenotype Count ÷ Total Outcomes) × 100
Genotype Ratio = Count of Each Genotype : Total Outcomes
Where:
- Favorable Outcomes: Number of desired genetic combinations
- Total Outcomes: Total number of possible genetic combinations
- Phenotype Count: Number of offspring showing a specific trait
- Genotype Ratio: Ratio of different gene combinations
These formulas ensure accurate genetic predictions for any monohybrid cross.
Example Calculation
Classic Aa × Aa Cross
| Genotype Outcome | Count | Percentage |
|---|---|---|
| AA | 1 | 25% |
| Aa | 2 | 50% |
| aa | 1 | 25% |
| Total Outcomes | 4 | 100% |
Genotype Ratio
1 AA : 2 Aa : 1 aa
Phenotype Ratio (Dominant Trait)
3 Dominant : 1 Recessive
Final Thoughts
Genetics can feel complex, but gene ratios follow clear and logical rules. The Gene Ratio Calculator turns these rules into simple results you can trust. Whether you are studying for an exam or exploring genetics out of curiosity, this tool provides clarity without unnecessary complexity.
By automating Punnett square calculations and ratio analysis, the calculator makes genetic inheritance patterns accessible to everyone, from beginners to advanced learners.