Western Hognose Genetics Calculator

Choose two parents, explore possible offspring, and see the expected odds for each outcome. Free to use, no account required.

No traits yet. Search below.

No traits yet. Search below.

Predicted offspring

Add at least one trait to each parent to see the odds.

Add traits to each parent, or type a morph name and the calculator fills in that morph's traits for you. It accepts:

Recessive genes, as visual or as het (one hidden copy): Albino, Axanthic, Sable, Toffee Belly, Swiss Chocolate, Lavender, Leucistic, Frost, Hypo, Pink Pastel Albino and Desert.
Anaconda and Superconda.
The Arctic and Antarctic gene: Arctic, Superarctic, Antarctic, Superantarctic and Antarctic Arctic.

Each parent holds one choice per gene, so picking Superconda replaces Anaconda, and picking Albino replaces Het Albino.

Each outcome shows its odds as a percentage and a fraction, whether it is visual, het only or wildtype, and its morph name.
Het percentages follow the hobby convention: among the babies that do not show a recessive gene, the share expected to carry it, rounded down. A 2/3 chance reads as 66% het.
Not documented marks a genetically valid combination that is not a named morph in the Hognose Hub morph guide. Its name is built from its traits.
Cards and List show the same outcomes in the same order. The Punnett breakdown shows one square per gene and how the squares multiply into the full list.
The example clutch is one random draw from the odds, not a prediction. Re-roll it to see how much real clutches can vary.

Only the genes listed above are calculated. Dominant and polygenic (line-bred) traits are not part of the calculation.
Parents are entered as visual or het. There is no input for a possible het, such as a 66% het parent.
Each gene is treated as inherited independently of the others.
Results are the expected odds for a pairing, not a guarantee for any single clutch.
Morph photos are not shown here. Documented morphs link to their page on Hognose Hub, where the community photos and credits live.
Nothing you enter is saved, and using the calculator never adds animals, pairings or clutches to a KeeperOS account.

How the calculator works

Add traits to each parent, or type a morph name and the calculator fills in that morph's traits for you. It accepts:

Recessive genes, as visual or as het (one hidden copy): Albino, Axanthic, Sable, Toffee Belly, Swiss Chocolate, Lavender, Leucistic, Frost, Hypo, Pink Pastel Albino and Desert.
Anaconda and Superconda.
The Arctic and Antarctic gene: Arctic, Superarctic, Antarctic, Superantarctic and Antarctic Arctic.

Each parent holds one choice per gene, so picking Superconda replaces Anaconda, and picking Albino replaces Het Albino.

Each outcome shows its odds as a percentage and a fraction, whether it is visual, het only or wildtype, and its morph name.
Het percentages follow the hobby convention: among the babies that do not show a recessive gene, the share expected to carry it, rounded down. A 2/3 chance reads as 66% het.
Not documented marks a genetically valid combination that is not a named morph in the Hognose Hub morph guide. Its name is built from its traits.
Cards and List show the same outcomes in the same order. The Punnett breakdown shows one square per gene and how the squares multiply into the full list.
The example clutch is one random draw from the odds, not a prediction. Re-roll it to see how much real clutches can vary.

Only the genes listed above are calculated. Dominant and polygenic (line-bred) traits are not part of the calculation.
Parents are entered as visual or het. There is no input for a possible het, such as a 66% het parent.
Each gene is treated as inherited independently of the others.
Results are the expected odds for a pairing, not a guarantee for any single clutch.
Morph photos are not shown here. Documented morphs link to their page on Hognose Hub, where the community photos and credits live.
Nothing you enter is saved, and using the calculator never adds animals, pairings or clutches to a KeeperOS account.