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Allele Frequency Calculator.

Calculate an allele's observed frequency from allele-copy counts.

On-device calculationNo signup
01

Set your values

Results update as you type.

Allele frequency: 0.4

Allele frequency

0.0000
Percentage: 40.00%

Percentage

0.00%

Educational arithmetic only. Inputs are explicit and calculations do not provide medical, veterinary, structural, or product recommendations.

Use Cases

Population Genetics Studies

Researchers can quickly compute allele frequencies to study genetic variation, evolution, and population structure.

Example: Calculate the frequency of a resistance allele in a sample of 200 alleles.

Educational Demonstrations

Students and educators can use this tool to illustrate Hardy-Weinberg equilibrium and allele frequency calculations in genetics courses.

Example: In a class exercise, compute the frequency of a dominant allele from given counts.

Frequently Asked Questions

What does the allele frequency calculator do?
It calculates the observed frequency of a specific allele by dividing the number of copies of that allele by the total number of allele copies in the population sample. You input the allele copies and total allele copies, and it returns the frequency.
How do I determine the total allele copies?
Total allele copies is the sum of all copies of the gene in your sample. For a diploid organism, it's twice the number of individuals (since each has two alleles). For example, 50 individuals would have 100 total allele copies.
Can this calculator be used for genotype frequency?
No, this calculator specifically computes allele frequency, not genotype frequency. Genotype frequency refers to the proportion of a particular genotype (e.g., AA, Aa, aa) in the population, which requires different input data.

Tips & Common Mistakes

Tips

  • Ensure that 'Allele copies' is the count of the specific allele you're interested in, not the genotype count.
  • Double-check that 'Total allele copies' is the sum of all alleles in the population, which is typically twice the number of individuals for diploid species.
  • Use the same unit for both inputs (e.g., counts, not percentages) to get an accurate frequency.
  • The result is a proportion between 0 and 1; multiply by 100 to express as a percentage.

Common Mistakes to Avoid

  • Confusing allele copies with genotype counts: For a diploid organism, each individual contributes two alleles, so genotype counts must be doubled to get allele counts.
  • Using the number of individuals as the total allele copies: This underestimates the total, leading to an inflated frequency.
  • Entering percentages instead of raw counts: The calculator expects counts, not percentages, so convert percentages to counts before input.

Last updated: August 13, 2026