Allele Frequency Calculator
Compute healthy (p) and mutant (q) allele frequencies and genotype frequencies (p², 2pq, q²) from recessive disease prevalence using Hardy–Weinberg.
This allele frequency calculator uses the Hardy–Weinberg equilibrium for an autosomal recessive trait: p² + 2pq + q² = 1 and p + q = 1.
Disease prevalence in the population is taken as q² (homozygous recessive). Then q = √q² and p = 1 − q. Carriers are at frequency 2pq; the “1 in X carriers” line uses 1 / (2pq).
You can enter prevalence as a proportion (1 in N people) or as a percentage. The other form is shown as a quick conversion below the input.
Compute allele and genotype frequencies from autosomal recessive disease prevalence using Hardy–Weinberg equilibrium (q² = disease frequency, then q = √q², p = 1 − q).
1 in 56 people = 1.7857%
Carrier frequency:
The mutant allele is present in 1 out of 4.32 people.
Our calculations:
- People with two healthy alleles (p²): p² = 0.7506
- People with one healthy and one mutant allele (2pq): 2pq = 0.23155
- People with two mutant alleles (q²): q² = 0.01786