Hardy–Weinberg Calculator: Calculate Allele/Genotype Frequencies

The Hardy-Weinberg Equilibrium Calculator is a versatile tool designed to analyze and predict allele and genotype frequencies within populations. This allele frequency calculator extends beyond the basic two-allele model to accommodate multiple alleles, making it valuable for calculating allele frequencies, determining genotype distributions, estimating carrier frequencies, and predicting genetic outcomes.

Choose your preferred information method of input in below calculator and get the allele and genotype frequencies in rules with Hardy-weinberg equilibrium equation.

Hardy-Weinberg Equilibrium Calculator

Hardy-Weinberg Equilibrium Calculator

The calculator below uses the Hardy-Weinberg equation to estimate the frequency of different genotypes for autosomal traits.

Select input of choice and fill values.

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Using the Calculator

Input Options

You can use this carrier frequency calculator with three input options:

  1. Percent of Population with Recessive Trait: Enter the percentage of the population that exhibits the recessive trait.
  2. Proportion of Population with Recessive Trait: Enter the proportion of the population with the recessive trait (e.g., if 1 in 400, enter 400).
  3. Input Allele Frequencies: Enter the frequencies of the alleles. Ensure the frequencies sum to 1. The calculator supports up to 5 alleles.

Number of Genotypes

For n alleles at a locus, the number of possible genotypes is the sum of the integers between 1 and n: Genotypes=n(n+1)/2

This means:

  • With 2 alleles, there are 1+2=3 genotypes.
  • With 3 alleles, there are 1+2+3=6 genotypes.
  • With 4 alleles, there are 1+2+3+4=10 genotypes.
  • With 5 alleles, there are 1+2+3+4+5=15 genotypes.

The calculator does not go beyond 5 alleles and 15 possible genotypes. However, you can use the above formula to calculate the number of genotypes for any number of alleles.

Understanding the Hardy-Weinberg Equilibrium Calculator

The Hardy-Weinberg principle is a fundamental concept in population genetics. It describes how allele and genotype frequencies remain constant in a population from generation to generation under certain conditions. These conditions include:

  • No Natural Selection: No allele confers a survival advantage.
  • Random Mating: Individuals pair by chance, not according to their genotypes.
  • No Mutation: No new alleles are introduced into the population.
  • No Migration: No new individuals enter or leave the population.
  • No Genetic Drift: The population is large enough to prevent random fluctuations in allele frequencies.

In essence, if these conditions are met, the population is said to be in Hardy-Weinberg equilibrium, meaning the genetic variation in the population will remain constant.

Allele Frequencies and Genotype Frequencies

For a trait with two alleles (p and q), the Hardy-Weinberg equation is expressed as: p2+2pq+q2=1 where:

  • p is the frequency of the dominant allele
  • q is the frequency of the recessive allele
  • p2 is the frequency of the homozygous dominant genotype
  • 2pq is the frequency of the heterozygous genotype
  • q2 is the frequency of the homozygous recessive genotype

Calculating Genotype Frequencies

The Hardy-Weinberg Equilibrium Calculator allows you to explore the relationship between allele frequencies and genotype frequencies in populations. The calculator also extends the Hardy-Weinberg equations to loci with more than two alleles.

Example Calculation: Sickle Cell Anemia

Sickle cell anemia is an autosomal recessive disorder where the hemoglobin gene has two alleles: HAHA​ (normal) and HSHS​ (sickle cell mutation).

For sickle cell anemia in a population, let’s assume the frequency of individuals with Sickle cell anemia (H_S H_S) is 1 in 400. This means:

q^2 = 1 / 400

q = sqrt(1 / 400) = 1 / 20

Since p + q = 1:

p = 1 – q = 1 – 1 / 20 = 19 / 20

Carrier frequency (2pq):

2pq = 2 * (19 / 20) * (1 / 20) = 38 / 400 = 0.095

Practical Application

The Hardy-Weinberg Equilibrium Calculator can be a valuable tool for understanding population genetics and the distribution of genetic traits. By experimenting with different allele frequencies and observing the resulting genotype frequencies, you can gain insights into the genetic structure of populations and the potential impact of evolutionary forces.

The Hardy-Weinberg principle provides a framework for studying genetic variation in populations. By ensuring the allele frequencies sum to one and understanding the conditions required for equilibrium, you can use this calculator to explore and predict the genetic makeup of populations. Whether you are a student, educator, or researcher, this tool can help you visualize and comprehend the complex relationships between alleles and genotypes in a population.

Limitations of the Hardy-Weinberg Equilibrium Calculator

The Hardy-Weinberg Equilibrium Calculator, while powerful, has limitations: it assumes ideal conditions (no selection, random mating, no mutation, no migration, no genetic drift), supports up to five alleles per locus, does not account for linkage disequilibrium, and assumes large population sizes. It ignores mutation rates and migration patterns, does not model evolutionary dynamics over time, focuses on single loci without considering multi-locus interactions, and assumes autosomal recessive inheritance for carrier frequency calculations. Despite these limitations, the calculator remains a valuable tool for basic genetic analysis and understanding population genetics principles.

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