Predicting the outcome of a breeding project is one of the most exciting aspects of reptile keeping. Whether you are a hobbyist or a professional breeder, understanding how genetics pass from parents to offspring is crucial. Use our professional Gecko Morph Calculator below to determine the probability of specific traits in your next clutch.
Parent 1 (Male)
Parent 2 (Female)
Expected Offspring:
Understanding Leopard Gecko Genetics
The world of Leopard Gecko (Eublepharis macularius) genetics is governed by the same Mendelian principles that apply to most living organisms. To use a morph calculator effectively, you must understand three primary types of inheritance: Recessive, Dominant, and Incomplete Dominant.
Recessive Traits
Recessive traits, such as Tremper Albino or Blizzard, require two copies of the gene (one from each parent) to be visually expressed. If a gecko has only one copy, it is "Heterozygous" (Het) for that trait. It looks like a normal gecko but carries the genetic code to pass the trait to its offspring.
Dominant and Incomplete Dominant Traits
Dominant traits only require one copy to be seen. However, in Leopard Geckos, we frequently see Incomplete Dominance, most notably in the Mack Snow morph.
- One copy of the gene results in a Mack Snow.
- Two copies of the gene results in a Super Snow, which looks significantly different from the single-gene version.
The Three Strains of Albino
A common mistake for beginners is mixing albino strains. There are three distinct strains: Tremper, Bell, and Rainwater. These are not compatible. If you breed a Tremper Albino to a Bell Albino, the offspring will be "Double Het" for both strains but will look like a normal wild-type gecko. Always ensure you know the specific lineage of your geckos before breeding.
Why Use a Morph Calculator?
Breeding reptiles is a long-term commitment. A morph calculator helps you avoid "genetic soup"—the practice of breeding unknown traits together, which can decrease the value and health of the animals. By using a calculator, you can plan your projects to produce healthy, predictable, and beautiful animals that contribute positively to the hobby.