p = frequency of dominant allele | q = frequency of recessive allele
What You Get with Our Free Hardy Weinberg Calculator
Complete Equilibrium Calculation
Enter any known value and calculate all Hardy Weinberg frequencies. p, q, p squared, 2pq, and q squared all determined from a single input.
Step by Step Working Shown
See the full mathematical process behind every calculation so you understand how each value is derived rather than just memorizing the Hardy Weinberg equation.
Allele and Genotype Frequencies
Calculate both allele frequencies p and q and genotype frequencies for homozygous dominant, heterozygous, and homozygous recessive populations.
Population Genetics Made Easy
Our calculator simplifies Hardy Weinberg equilibrium calculations for biology students, genetics courses, and AP Biology exam preparation.
Chi Square Test for Equilibrium
Determine whether a population is actually in Hardy Weinberg equilibrium by comparing observed and expected genotype frequencies with a built in chi square analysis.
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No account needed, no download required, no limits at all. Calculate Hardy Weinberg equilibrium as many times as you want completely free right now.
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Why Our Hardy Weinberg Calculator Gets It Right
The Hardy Weinberg equation p squared plus 2pq plus q squared equals 1 describes the genotype frequencies of a population in genetic equilibrium. Despite the equation looking simple applying it correctly requires understanding which value you have, which you need to calculate, and how to work through the algebra to get there. Students frequently make errors when starting from q squared and forgetting to take the square root before calculating p or when confusing allele frequencies with genotype frequencies.
Our Hardy Weinberg calculator accepts any known value as the starting input and derives everything else automatically with each step shown. If you know the frequency of homozygous recessive individuals you enter q squared and the calculator derives q, then p, then p squared, then 2pq with the algebra visible at every stage. This step by step approach serves as both a calculation tool and a learning resource.
The chi square equilibrium test adds a layer of analysis that most Hardy Weinberg calculators skip. Knowing the theoretical equilibrium frequencies is only half the picture. Comparing them to observed population data using chi square analysis tells you whether evolutionary forces like natural selection, genetic drift, or non random mating are acting on the population. Our calculator includes this analysis so you can determine whether the Hardy Weinberg assumptions actually hold for your specific data.
Explore more free science calculator tools: Dihybrid Cross Calculator, BMI Calculator, and our full Calculator Tools collection. Learn about Hardy Weinberg equilibrium at Wikipedia.
How Hardy Weinberg Calculator Works
Calculate Hardy Weinberg equilibrium in four simple steps.
Enter Your Known Value
Input any known frequency. Allele frequency p or q, genotype frequency p squared, 2pq, or q squared, or the number of individuals with a specific phenotype.
Click Calculate
Hit calculate and get all five Hardy Weinberg equilibrium values instantly with the step by step mathematical derivation shown clearly.
Review the Working
Follow the step by step algebra to understand how each value was derived from your input. Verify the logic matches your coursework expectations.
Apply to Your Problem
Use the calculated frequencies for your genetics homework, lab report, AP Biology exam question, or population genetics research.
Frequently Asked Questions About Hardy Weinberg Calculator
Here are answers to the most common questions about Hardy Weinberg calculators, how the equilibrium equation works, and how to apply it in population genetics problems.
What is a Hardy Weinberg calculator?
It calculates allele and genotype frequencies for a population using the Hardy Weinberg equilibrium equation p squared plus 2pq plus q squared equals 1 from any single known input value.
What is the Hardy Weinberg equation?
The equation states that p squared plus 2pq plus q squared equals 1 where p and q are allele frequencies and the three terms represent homozygous dominant, heterozygous, and homozygous recessive genotype frequencies.
What does Hardy Weinberg equilibrium mean?
A population is in Hardy Weinberg equilibrium when allele and genotype frequencies remain constant across generations. This requires no natural selection, no mutation, no migration, random mating, and a large population.
How do I find q from q squared?
Take the square root of q squared to find q. For example if the frequency of homozygous recessive individuals is 0.16 then q equals the square root of 0.16 which is 0.4.
Is this Hardy Weinberg calculator completely free?
Yes. No signup, no download, no usage limits. Calculate Hardy Weinberg equilibrium values as many times as you need at zero cost.
What is homozygous dominant in Hardy Weinberg?
Homozygous dominant individuals carry two copies of the dominant allele. Their frequency in the population is represented by p squared in the Hardy Weinberg equation.