Hardy-Weinberg Equilibrium Calculator
Results:
| Genotype | Expected Count | Observed Count |
|---|---|---|
| Common Homozygotes (AA) | — | — |
| Heterozygotes (Aa) | — | — |
| Rare Homozygotes (aa) | — | — |
The Hardy-Weinberg Equation:
2pq = heterozygous frequency (Aa)
q2 = recessive homozygous frequency (aa)
Hardy–Weinberg Equilibrium
The Hardy–Weinberg Equilibrium describes how, in a large and randomly mating population with no evolutionary pressures, the frequencies of alleles and genotypes remain constant across generations. This concept provides a baseline for understanding genetic variation and detecting evolutionary change.
For a population to stay in Hardy–Weinberg equilibrium, five key conditions must be satisfied: no mutations, random mating, no natural selection, an infinitely large population size (so that chance effects are negligible), and no migration introducing or removing alleles.
How This Calculator Works
This calculator estimates allele frequencies and applies the Hardy–Weinberg equation to compute the expected numbers of homozygous dominant, heterozygous, and homozygous recessive individuals based on observed genotype counts for a two-allele system.
It also performs a Chi-squared test, reporting both the test statistic and the p-value. These results let you assess whether your observed data significantly deviates from Hardy–Weinberg expectations, indicating that the population may not be in equilibrium.
With this tool you can:
- Estimate allele frequencies (p and q) directly from observed genotype counts.
- Predict expected genotype distributions under Hardy–Weinberg assumptions.
- Run a Chi-squared test to evaluate whether the observed vs. expected counts differ enough to be statistically significant.
- A very small p-value (commonly < 0.05) suggests a departure from equilibrium.
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