Reptile Genetics Calculator
Calculate offspring morph probabilities across multiple traits simultaneously. Select a sire and dam, choose their morph and het status, and get exact percentages for every possible outcome -- including named combo morphs.
Free, no account required. Powered by the same genetics engine as the ReptiDex mobile app.
Axolotl
Open Axolotl genetics calculator
Ball Python
Open Ball Python genetics calculator
Bearded Dragon
Open Bearded Dragon genetics calculator
Boa Constrictor
Open Boa Constrictor genetics calculator
Corn Snake
Open Corn Snake genetics calculator
Crested Gecko
Open Crested Gecko genetics calculator
Hognose Snake
Open Hognose Snake genetics calculator
Leopard Gecko
Open Leopard Gecko genetics calculator
Multi-trait morph probability
Most genetics calculators handle one gene at a time. ReptiDex resolves all selected loci simultaneously, then matches results against a curated combo morph database to surface named outcomes directly in the results.
Homozygous required
Two copies needed to visually express. Carriers (hets) are phenotypically normal but pass the allele to offspring. Examples: albino, axanthic, piebald.
Het and super are distinct
A single copy produces one visual form; two copies produce a different, usually more extreme form. Examples: pastel/super pastel, spider/bumblebee.
Single copy expresses
One copy is sufficient for visual expression. Supers may be identical or lethal depending on the gene. Examples: pinstripe, highway, monsoon.
Frequently asked questions
Can I calculate multiple traits at once?
Yes. Select any combination of morphs and het statuses for both parents and the calculator resolves all loci simultaneously. Named combo morphs are identified in the results automatically.
How accurate is the probability data?
Probabilities are mathematically exact given the input genotypes. Accuracy depends on the parents being correctly genotyped. The calculator assumes standard Mendelian inheritance with loci on independent chromosomes.
What does "possible het" mean?
A possible het (or visual het) indicates the animal may carry one copy of a recessive gene but has not been proven through breeding. The calculator treats possible hets as definite hets for probability purposes.
Why do some species have more morphs than others?
Genetics data is added species by species as it is curated and verified. Ball pythons have the largest database reflecting decades of captive breeding. Additional species are added on an ongoing basis.
Is this the same calculator used in the ReptiDex app?
Yes. The web calculator and mobile app share the same genetics engine. The mobile app additionally saves pairing records, links results to your collection, and tracks breeding outcomes over time.
Track your pairings in the app
The ReptiDex mobile app saves your pairing calculations, links them to your collection, and tracks breeding outcomes across seasons.
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