Genetics Calculators
Allele Frequency Calculator
Calculate population allele frequencies p and q from AA, Aa, and aa genotype counts using the standard population genetics formula.
Chromosome Number Calculator
Look up standard diploid and haploid chromosome counts for common species from fruit flies to dogs, with the haploid count derived automatically.
DNA Molecular Weight Calculator
Calculate the molecular weight of double-stranded DNA from base pair count or single-stranded DNA from its exact sequence and base composition.
Genetic Relatedness Calculator
Look up the standard coefficient of relatedness and approximate shared DNA percentage for common family relationships, from siblings to second cousins.
Hardy-Weinberg Calculator
Calculate expected Hardy-Weinberg genotype frequencies from an allele frequency, or run a chi-square test to check observed counts against equilibrium.
Heterozygosity Calculator
Compare observed heterozygosity from a sample against the Hardy-Weinberg expected heterozygosity derived from allele frequency, side by side.
Inbreeding Coefficient Calculator
Calculate the inbreeding coefficient F for a pedigree using Wright's path-counting method from ancestor path lengths and shared ancestry.
PCR Primer Tm Calculator
Calculate PCR primer melting temperature using the Wallace rule for short primers or the GC formula for longer primers, from the actual sequence.
Punnett Square Calculator
Build a full Punnett square for any two-letter genotype cross and get exact genotype and phenotype ratios for the offspring, not just an estimate.
Recombination Frequency Calculator
Calculate recombination frequency and estimated genetic map distance in centiMorgans from recombinant and total offspring counts in a genetic cross.
From a Single Cross to Whole-Population Genetics
Genetics calculations scale from a single Punnett square predicting one cross's offspring ratios, up to Hardy-Weinberg equilibrium describing allele frequencies across an entire population over generations. Ten calculators here cover both classical Mendelian genetics and the population genetics used in evolutionary biology and conservation work.
Popular Genetics Calculators
Ten tools span inheritance, population genetics, and molecular genetics:
- Punnett Square Calculator — predicts offspring genotype and phenotype ratios from parental genotypes.
- Hardy-Weinberg Calculator — calculates expected allele and genotype frequencies in a population at equilibrium.
- Allele Frequency Calculator — finds the proportion of a specific allele within a population's gene pool.
- Inbreeding Coefficient Calculator — estimates the probability that an individual has two identical alleles inherited from a common ancestor.
- PCR Primer Tm Calculator — estimates primer melting temperature for PCR reaction design.
Why Hardy-Weinberg Is a Baseline, Not a Prediction
The Hardy-Weinberg equilibrium describes what allele frequencies would look like in a population under a specific set of idealized conditions — no mutation, no migration, no selection, random mating, and infinite population size — which almost never fully holds in a real population. That's precisely its value: geneticists compare observed genotype frequencies against the Hardy-Weinberg expectation, and a significant deviation is itself evidence that one of those assumptions is being violated, whether through natural selection, genetic drift in a small population, or non-random mating.
Frequently Asked Questions
Can a Punnett square predict exact outcomes for a single offspring?
No — it predicts probabilities across many offspring; any single cross can still produce an "unlikely" outcome purely by chance, similar to how a coin can land heads five times in a row despite 50/50 odds.
Why does inbreeding coefficient matter in conservation biology?
Small, isolated populations accumulate higher inbreeding coefficients over generations, which increases the expression of harmful recessive traits and is a key concern in breeding programs for endangered species.
Explore More
Working at the organism or ecosystem level instead? See the Biology Calculators, or check reaction-level chemistry in the Chemistry Calculators.