What this calculator does
The Allele Frequency Calculator uses genotype counts from a sample population to calculate the frequency of each allele, then predicts what the genotype frequencies would look like if the population were in Hardy-Weinberg equilibrium.
The formula it uses
Allele frequencies are calculated as p = (2×AA + Aa) / 2N and q = (2×aa + Aa) / 2N, where N is the total number of individuals counted. Under Hardy-Weinberg equilibrium, expected genotype frequencies are then p² (AA), 2pq (Aa), and q² (aa).
- p + q always equals 1
- p² + 2pq + q² always equals 1
A note on accuracy
Hardy-Weinberg equilibrium assumes no mutation, migration, selection, or genetic drift, and random mating within a large population. Real populations often deviate from these assumptions, so this calculator is intended for general education and coursework rather than field research conclusions.