Allele & Genotype Frequency Calculator

Summary

Enter genotype counts (AA, Aa, aa) or allele frequency p to compute allele and genotype frequencies, plus a chi-square test for Hardy-Weinberg equilibrium.

How it works

1. Select Mode 1 to calculate from observed genotype counts, or Mode 2 to predict from allele frequency p.
2. Mode 1: Enter counts for each genotype (AA, Aa, aa). The tool computes N, p, q, observed frequencies, and HWE-expected frequencies.
3. Mode 1 also runs a chi-square goodness-of-fit test (df = 1) when N >= 5.
4. Mode 2: Enter allele frequency p (0 < p < 1). q is derived as 1 - p, and genotype frequencies are p², 2pq, q².
5. All frequencies are rounded to 4 decimal places.

Use cases

• Calculate allele frequencies from population genotype survey data.
• Predict Hardy-Weinberg expected genotype frequencies from allele frequencies.
• Test whether a sample population deviates from Hardy-Weinberg equilibrium.
• Verify genetics homework or lab report calculations.
• Estimate carrier frequency of a recessive allele in a population.
• Explore how changing p alters expected genotype distributions.

Frequently Asked Questions