Equine Color Genetics Calculator
Predict your foal's exact coat color probabilities instantly. Select the genetic makeup of the sire and dam below to generate accurate breeding forecasts based on Mendelian genetics.
Predicted Foal Coat Colors
How to Use the Equine Color Genetics Calculator
Welcome to the most advanced and user-friendly colour calculator for horses on the web. Whether you are a professional breeder planning your next season or an enthusiast curious about equine genetics, our foal color calculator provides instant, accurate mathematical probabilities for your foal's future coat.
To use the tool, simply input the genetic makeup of the sire (stallion) and the dam (mare). If you have a DNA panel from a laboratory, select the exact alleles (e.g., E/e for Extension, A/a for Agouti). If you don't have DNA test results, you can estimate the genes based on the horse's visual appearance (phenotype) and the colors of its parents or previous offspring.
Understanding Horse Coat Color Genetics
The foundation of every horse breeding calculator is based on Mendelian inheritance. Every horse receives one gene copy (allele) from its sire and one from its dam. The interaction of these dominant and recessive genes determines the final coat color.
Base Colors: The Extension and Agouti Genes
Every single horse, regardless of whether they appear white, palomino, or roan, genetically starts as one of three base colors: Black, Bay, or Chestnut. This is determined by two primary genes:
- The Extension Gene (Red/Black Factor): This gene controls the production of black pigment. The dominant allele "E" produces black pigment, while the recessive "e" produces red. A horse with "e/e" will be Chestnut, incapable of producing black hair.
- The Agouti Gene (A): If a horse has at least one dominant "E" (meaning they can produce black pigment), the Agouti gene determines where that black pigment goes. A dominant "A" restricts black to the points (legs, mane, tail), creating a Bay. Recessive "a/a" leaves the black pigment uniformly distributed, resulting in a Black horse. Agouti has no visible effect on Chestnut horses.
The Dilute Gene Calculator (Cream and Gray)
Once the base color is established, modifier genes can alter the appearance. Our dilute gene calculator for horses includes the most common modifiers:
The Cream Gene (CR) is an incomplete dominant gene that lightens red and black pigment. A single copy (CR/n) dilutes a chestnut to a Palomino, a bay to a Buckskin, and a black to a Smoky Black. Two copies (CR/CR) result in double dilutes: Cremello, Perlino, and Smoky Cream.
The Gray Gene (G) is dominant. If a foal inherits even one Gray allele (G/n), it will progressively lose its hair pigment over time, eventually turning white or dapple gray, regardless of its underlying base color. The horse's true genetic color is "masked" by the graying process.
Frequently Asked Questions (F.A.Q.)
How accurate is a horse colour calculator?
A horse colour calculator is extremely accurate, operating on the established laws of Mendelian genetics. If the exact genetic makeup (genotype) of both the sire and dam is known through DNA testing, the calculator provides the exact mathematical probability of each possible coat color for the foal. However, if you are guessing the parents' genetics based solely on their appearance, the results will be an estimation.
Can two black horses produce a chestnut foal?
Yes, absolutely. Black is dominant over chestnut (red). If both black horses are heterozygous for the Extension gene (meaning they carry one Black 'E' allele and one Red 'e' allele, written as E/e), there is a 25% mathematical probability that they will both pass on the recessive 'e' allele. This e/e combination results in a chestnut foal.
What is a dilution gene in horse breeding?
A dilution gene in horse breeding is a specific gene that lightens the base coat color. The most common is the Cream (CR) gene. A single cream gene (CR/n) dilutes a chestnut horse to a palomino, and a bay horse to a buckskin. Two cream genes (CR/CR) create double dilutions, such as cremello or perlino. Other dilute genes include Dun, Champagne, and Silver.
Do I need a DNA test for my horse to use the calculator?
While you do not strictly need a DNA test to use the equine color genetics calculator, having one significantly improves the accuracy of your results. Many horses hide recessive genes (like a bay hiding a chestnut gene). Without a DNA color panel, you can run the calculator using estimated genotypes, but the percentages will be predictive rather than definitive.