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Dog Punnett Square Calculator

Calculate the probability of each genotype and phenotype in a dog litter using a Punnett square for any single gene trait.

🧬 Dog Punnett Square Calculator
Enter your dog's details below to get an instant result.
Expected Offspring Ratios
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What Is the Dog Punnett Square Calculator?

Calculate the probability of each genotype and phenotype in a dog litter using a Punnett square for any single gene trait.

The Punnett square is the foundational tool of Mendelian genetics — it predicts the probability of each possible genotype and phenotype in offspring based on the parental genotypes. For dog breeders, it helps predict coat colour, coat type, disease carrier status, and other single-gene traits before breeding occurs.

Every result is based on published veterinary research and breed-size-specific growth data — not generic averages. This tool is completely free, works instantly in your browser, and requires no account or sign-up.

How to Use This Calculator

1
Enter Your Dog's Details

Fill in the required fields above — typically your dog's weight, age, or breed size. Every field has a clear label and hint.

2
Click Calculate

Press the calculate button to get your instant result. No page reload, no account needed, no waiting.

3
Review Your Result

Your result appears immediately below the calculator. It includes the primary answer plus additional context where relevant.

4
Use the Information

Share, print, or save your result. Always discuss health-related results with your veterinarian before making decisions.

How It Works

Mendelian inheritance works through dominant and recessive alleles at a gene locus. Each parent contributes one allele to each offspring. A Punnett square maps all possible allele combinations to show the probability of each genotype (e.g. BB, Bb, bb) and phenotype (expressed trait). Dominant alleles (shown in uppercase) are expressed when at least one copy is present. Recessive alleles (lowercase) are only expressed when two copies are present (homozygous recessive).

Common single-gene traits in dogs include: B locus (black/brown pigment — BB or Bb = black, bb = brown/chocolate), E locus (extension — ee = yellow regardless of B locus), and many genetic health conditions (PRA, degenerative myelopathy, etc.).

Sources: Schmutz SM, Berryere TG. Genes affecting coat colour and pattern in domestic dogs. Animal Genetics 2007; Strain GM. Genetics of deafness in domestic animals. Front Vet Sci 2015.

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Veterinary Research

Every formula is derived from peer-reviewed veterinary studies and clinical guidelines, not guesswork or generic rules.

Instant Results

No page reload, no waiting, no account needed. Enter your details and your result appears immediately.

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100% Private

All calculations happen in your browser. Nothing you enter is ever stored on our servers or shared with anyone.

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Always Free

Every calculator on Doggy Calculators is and will always be completely free to use — no premium tier, no catch.

Frequently Asked Questions

What is a Punnett square used for in dog breeding?+
A Punnett square predicts the probability of each genotype and phenotype appearing in a litter based on the parents' known genotypes. Breeders use it to predict coat colours, pattern probabilities, and — most importantly — the risk of producing offspring affected by or carrying recessive genetic diseases like progressive retinal atrophy (PRA), degenerative myelopathy (DM), or hereditary cataract.
What does "carrier" mean in dog genetics?+
A carrier dog has one copy of a recessive allele (heterozygous — Aa) but does not express the associated trait or disease. Carriers can only produce affected offspring (aa) if bred to another carrier or an affected dog. DNA testing identifies carriers so breeders can make informed mating decisions — typically breeding carriers only to clear (AA) dogs to avoid affected offspring.
Why should I never breed two merle dogs together?+
Double merle (MM) dogs — produced when two merle-pattern dogs are bred — have a very high probability of severe ocular and auditory defects including microphthalmia, anophthalmia, and bilateral deafness. A merle × merle pairing produces 25% double merle offspring statistically. Most kennel clubs prohibit merle × merle breeding for this reason.

Sources & References

This calculator's formulas are based on the following peer-reviewed and authoritative veterinary sources:

⚠️ These calculators are reference tools only. Always consult a licensed veterinarian before administering medication or making medical decisions.