Genetics & evolution · SL/HL
Allele Frequency from Genotype Counts Calculator
Enter the observed genotype counts for a diploid population.
Your values
Start with the example or enter your own values. Use a dot for decimals and e for scientific notation.
Calculated locally. No account or input upload.
Result & working
ExampleThe calculator is loading. The worked example is also shown below.
Step-by-step working
The formula
p = (2AA + Aa)/(2N)
q = (2aa + Aa)/(2N)
p + q = 1
| Symbol | Meaning |
|---|---|
| N | Total number of individuals. |
When to use this calculator
This calculates observed allele frequencies; it does not by itself show whether the population is in Hardy–Weinberg equilibrium.
Worked example
The page opens with these example values. The result below is pre-generated for reference.
- N = 36+48+16 = 100
- p = (2AA + Aa)/(2N) = (2×36+48)/200 = 0.6
- q = (2aa + Aa)/(2N) = (2×16+48)/200 = 0.4
- p + q = 1
p = 0.6, q = 0.4
Common mistakes
- Count two alleles per diploid individual.