Biology
Hardy-Weinberg Equilibrium Calculator
From one allele frequency, see the genotype frequencies a population would show under Hardy-Weinberg equilibrium.
Your inputs
Change any value to update the result instantly.
Heterozygotes (2pq) in the population
48 %
Frequency of allele a (q)
0.4
Homozygous dominant AA (p²)
36 %
Homozygous recessive aa (q²)
16 %
Equilibrium holds only when there is no mutation, migration, selection or drift, and mating is random in a large population. Comparing real counts to these expected values is how scientists detect evolution at work.
What this calculator does
Computes expected genotype frequencies (p², 2pq, q²) from an allele frequency under Hardy-Weinberg equilibrium.
What your result means
The percentages are the genotype shares expected in a non-evolving, randomly mating population.
Formula and working
p² + 2pq + q² = 1, with q = 1 − p
- 1
Collect the inputs
Frequency of allele A (p) = 0.6
- 2
Apply the formula
p² + 2pq + q² = 1, with q = 1 − p
- 3
Result
Heterozygotes (2pq) in the population = 48 %
Frequently asked questions
Symbols and assumptions
- p
- Frequency of allele A
- q
- Frequency of allele a = 1 − p
- p², 2pq, q²
- Expected frequencies of AA, Aa, aa
- • No mutation, migration, selection or genetic drift; random mating; large population.
Sources and review
Reviewed 2026-09-22 · Next review 2027-09-22
- • Real populations deviate; comparing observed counts to these expectations is itself the test for evolution.
Important limitation
This is an educational estimate based only on the values and formula shown. Verify current rates, rules, units, and professional standards before relying on the result. It is not personalized financial or investment advice.
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