Punnett Square Calculator
Calculate punnett square instantly in your browser — the published formula, worked locally with no data sent anywhere.
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What this tool does
Calculate punnett square instantly in your browser — the published formula, worked locally with no data sent anywhere. Classical Mendelian inheritance: genes assort independently, alleles are fully dominant or recessive, and all gametes are equally likely. Linked genes, codominance, lethal alleles and sex linkage break the textbook ratios (the dihybrid 9:3:3:1 among them).
How to use the Punnett Square Calculator
- Enter or select cross type.
- Enter or select parent 1 genotype (e.g. aa, or aabb for dihybrid).
- Enter or select parent 2 genotype.
- Read the calculated result; change any measurement to compare alternatives.
Formula
Enumerate each parent's gametes (one allele per gene), combine every pair, and tally the offspring genotypes; a phenotype shows the dominant trait for a gene whenever at least one capital (dominant) allele is present.
- cross
- Cross type
- p1
- Parent 1 genotype (e.g. Aa, or AaBb for dihybrid)
- p2
- Parent 2 genotype
Classical Mendelian inheritance: genes assort independently, alleles are fully dominant or recessive, and all gametes are equally likely. Linked genes, codominance, lethal alleles and sex linkage break the textbook ratios (the dihybrid 9:3:3:1 among them).
Worked example
For punnett square calculator, the following measurements illustrate the exact method: Cross type: mono; Parent 1 genotype (e.g. Aa, or AaBb for dihybrid): Aa; Parent 2 genotype: Aa.
Inputs
- Cross typeMonohybrid (1 gene)
- Parent 1 genotype (e.g. Aa, or AaBb for dihybrid)Aa
- Parent 2 genotypeAa
Result
- Distinct offspring genotypes3
- Total combinations in the square4
- Phenotype — A (dominant) (%)75
- Phenotype — a (recessive) (%)25
Results explained
- Distinct offspring genotypes
- Distinct offspring genotypes from the formula above. Classical Mendelian inheritance: genes assort independently, alleles are fully dominant or recessive, and all gametes are equally likely. Linked genes, codominance, lethal alleles and sex linkage break the textbook ratios (the dihybrid 9:3:3:1 among them).
- Total combinations in the square
- Total combinations in the square from the formula above. Classical Mendelian inheritance: genes assort independently, alleles are fully dominant or recessive, and all gametes are equally likely. Linked genes, codominance, lethal alleles and sex linkage break the textbook ratios (the dihybrid 9:3:3:1 among them).
- Phenotype — A (dominant) (%)
- Phenotype — A (dominant) (%) from the formula above. Classical Mendelian inheritance: genes assort independently, alleles are fully dominant or recessive, and all gametes are equally likely. Linked genes, codominance, lethal alleles and sex linkage break the textbook ratios (the dihybrid 9:3:3:1 among them).
- Phenotype — a (recessive) (%)
- Phenotype — a (recessive) (%) from the formula above. Classical Mendelian inheritance: genes assort independently, alleles are fully dominant or recessive, and all gametes are equally likely. Linked genes, codominance, lethal alleles and sex linkage break the textbook ratios (the dihybrid 9:3:3:1 among them).
Frequently asked questions
Enumerate each parent's gametes (one allele per gene), combine every pair, and tally the offspring genotypes; a phenotype shows the dominant trait for a gene whenever at least one capital (dominant) allele is present.
Classical Mendelian inheritance: genes assort independently, alleles are fully dominant or recessive, and all gametes are equally likely. Linked genes, codominance, lethal alleles and sex linkage break the textbook ratios (the dihybrid 9:3:3:1 among them).
Every field is labelled with its unit — enter values in exactly the labelled unit and read the result in the labelled output unit. Fields with a unit symbol also support the site-wide imperial/metric switch, which converts before the formula runs.
It uses double-precision arithmetic and the published constants and formulas named on this page. The last displayed digit may be rounded, and real conditions can differ from the idealized model described in the assumptions.
Yes. Every calculation runs entirely in your browser; nothing you enter is uploaded, stored or shared.