Allele Frequency Calculator

Work out allele frequency instantly with clear inputs, formula shown and shareable results.

About Allele Frequency Calculator

Counts alleles directly from genotype numbers: each homozygote contributes two copies and each heterozygote one.

Formula

Gene counting

p = (2 x homozygous dominant + heterozygous) / (2 x total individuals); q = 1 - p

Worked example

With the default values below, Allele Frequency Calculator returns Dominant allele frequency of 0.55000. Change any input above and every figure here is recalculated in your browser.

Inputs used

Homozygous dominant individualsaccepts 0–10,000,000: 320
Heterozygous individualsaccepts 0–10,000,000: 460
Homozygous recessive individualsaccepts 0–10,000,000: 220

Results

Dominant allele frequency: 0.55000
Recessive allele frequency: 0.45000
Individuals counted: 1,000
Alleles counted: 2,000

Step by step

1Values used
2Gene counting
3Dominant allele frequency= 0.55000
4Recessive allele frequency= 0.45000
5Individuals counted= 1,000
6Alleles counted= 2,000

Assumptions and limits

The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 5 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

Does this assume Hardy-Weinberg?

No. Direct gene counting works whatever the mating structure, which is why it is preferred when genotypes are observable.

What if only phenotypes are known?

Then q must be estimated as the square root of the recessive phenotype frequency, which does assume equilibrium.