Calculate Breeding Outcomes
Select the morphs of both parent snakes to see the predicted genetic outcomes
Parent 1
Parent 2
Understanding Ball Python Genetics
What is a Ball Python Morph?
A Ball Python morph is a genetic variation that affects the snake’s color and pattern. These variations are the result of selective breeding and genetic mutations. Ball Pythons (Python regius) are one of the most genetically diverse reptiles in the pet trade, with thousands of possible color and pattern combinations.
Types of Genetic Inheritance
Recessive Genetics
Recessive morphs require two copies of the gene (one from each parent) to be visually expressed. A snake with only one copy is called “heterozygous” or “het” and will appear normal but can pass the trait to offspring.
Examples: Albino, Piebald, Clown, Axanthic
Het Albino × Het Albino = 25% Albino, 50% Het Albino, 25% Normal
Co-dominant Genetics
Co-dominant morphs show visible changes with just one copy of the gene. When two copies are present, they produce a “super form” with even more dramatic appearance.
Examples: Pastel, Mojave, Spider, Banana, Fire, Lesser
Pastel × Pastel = 25% Super Pastel, 50% Pastel, 25% Normal
Dominant Genetics
Dominant morphs express their traits whether the snake has one or two copies of the gene. Unlike co-dominant genes, the super form typically looks the same as the single-gene version.
Examples: Pinstripe, Blackhead
Pinstripe × Normal = 50% Pinstripe, 50% Normal
What Does “Het” Mean?
“Het” is short for heterozygous, meaning the snake carries one copy of a recessive gene but doesn’t visually display it. Het snakes are valuable in breeding programs because they can produce the recessive morph when paired with another het or visual morph.
Example: A “Het Piebald” looks like a normal Ball Python but carries the Piebald gene and can produce Piebald offspring when bred properly.
Morph Library
Browse all 40+ Ball Python morphs, filter by genetic type, and learn about each morph
Frequently Asked Questions
How accurate is this calculator?
The calculator uses Mendelian genetics principles and is highly accurate for predicting probability percentages. However, actual breeding outcomes may vary due to factors like incomplete dominance, polygenic traits, and random chance.
Can I calculate multi-gene morphs?
Currently, the calculator supports single-gene morphs. Multi-gene combinations (like Banana Pastel) will be added in future updates. Stay tuned!
What does “Het” mean?
“Het” is short for heterozygous. It means the snake carries one copy of a recessive gene but doesn’t visually display the trait. Hets are crucial for breeding recessive morphs.
Why does the calculator warn about certain pairings?
Some morphs have known health issues (like Spider wobble syndrome) or lethal combinations (like Super Spider). The calculator displays warnings to help breeders make ethical, informed decisions.
Is this calculator free?
Yes! This calculator is 100% free to use with no registration required. Our goal is to provide accessible genetics education for the Ball Python community.
How do I report a bug or suggest a feature?
We’d love to hear from you! Please contact us through our website’s contact form or email us directly. We’re constantly improving the calculator based on user feedback.