equine color calculator

How this equine color calculator works

This calculator estimates foal color probabilities using Mendelian inheritance at three major loci that influence many common horse coat outcomes. It does not guess your horse's genotype from photos; instead, it calculates expected percentages once you select likely genotypes for both parents.

Genes included in this model

• Extension (E/e): controls black pigment production. Foals with ee are red-based (chestnut/sorrel).
• Agouti (A/a): distributes black pigment. On black-capable horses (E_), A_ usually creates bay points, while aa allows full black expression.
• Cream (Cr): dilution gene. One copy dilutes red pigment strongly and black pigment mildly; two copies produce double-dilute colors.

Phenotypes predicted

From the three-locus combinations, the calculator predicts these familiar outcomes:

• Chestnut / Sorrel
• Bay
• Black
• Palomino
• Buckskin
• Smoky Black
• Cremello
• Perlino
• Smoky Cream

Reading your results

After calculating, you will see a ranked probability table. The top row is the most likely foal phenotype under the assumptions you entered. You will also see genotype distributions at each locus, which can help when planning test breeding, selecting genetic tests, or understanding why rare outcomes are still possible.

Important interpretation tips

• Probabilities describe large averages over many foals, not guarantees for a single foal.
• If parental genotypes are uncertain, run multiple scenarios to see how results shift.
• Some colors can look similar at birth and change with age, season, and sun bleaching.

Why genotype testing still matters

A calculator is only as good as the inputs. If your breeding decisions depend on specific outcomes, DNA testing for Extension, Agouti, and Cream can dramatically improve prediction quality. For many breeders, this reduces surprises and helps match breeding goals with realistic expectations.