Genetics · coat colors
Coat calculator
What coat could your foal have? Describe the coats of its two parents or enter their known genotypes. The calculator shows which coats the foal could inherit and the chance of each one.
Start with what you know about the mother and father. You can describe their coats without knowing genetic symbols, or enter all ten genotype pairs if those are known. The help beside each field explains the choices.
- Choose “Observed coat” to describe what a parent looks like, or “Known genotypes” if you can complete all ten pairs. Each pair describes two inherited variants at one genetic location, one from each of that horse’s parents. Never use N/N to stand for an unknown result.
- A coat name can fill in the starting details. Check the base color, then describe any other effects you recognize. For a horse born bay that later turns gray, enter a bay base and graying present. Leave traits you cannot assess unknown.
- In “Observed coat” mode, you can select a breed so the calculation can use published study data to help estimate some unknown traits. This does not confirm that the horse carries any particular variant. Where suitable data are missing, all compatible genotypes are treated as equally likely.
- When both parents are ready, select “See possible coats”. First compare the base colors and coat groups, then open a group to explore other effects. After changing an answer, calculate again to update the results.
Choose “Unknown” if you cannot recognize a trait or do not have enough information. The calculator keeps the combinations that fit the other answers. For example, leaving Gray unknown keeps both gray and non-gray possibilities unless another supplied detail rules one out.
Choose “Present” when you recognize the effect. Choose “Not visible” when you have assessed the coat and do not see it. This remains an observation, rather than a negative DNA result: Pearl can be carried without showing, and Silver stays hidden on chestnut. Frame Overo and Leopard Complex offer only present or unknown, because a horse with subtle markings can still carry the variant.
The three base colors add up to 100%. Coat groups then combine a base with a defining dilution: buckskin, for example, is bay with one Cream copy. Each group’s main percentage refers to all conceptions. Open the group to see trait percentages that apply only within it. Several traits can occur in the same foal, so these percentages must not be added together.
A 50% result means a one-in-two chance at each conception, given the information and assumptions used. Two successive foals can have the same coat; the percentage does not guarantee one of each outcome in two births. When parental traits are unknown, the result also depends on how the remaining genetic possibilities are weighted.
This calculator models the horse coat traits available in the form. Other patterns, such as Tobiano and Sabino, are not included. The results show possible coat types; they do not predict the exact shade or shape of the markings. These results apply to horses, not donkeys or other equids.
What coat could the foal have?
Enter the mare’s and stallion’s coat descriptions or known genotypes, then select “See possible coats”. The help beside each field explains what to look for and how to read the genetic symbols.