Predict your foal's coat colors and patterns from the sire's and dam's genetic test results.
The Equine Color Calculator predicts the possible coat colors and patterns of a foal from the sire's and dam's genotypes. Select each parent's result for 10 color genes, press Calculate Foal Colors, and the calculator lists every possible foal color with its probability.
Foal coat color is set by genes, not by the parents' appearance alone. A bay stallion can carry a hidden red gene. A chestnut mare can carry a hidden agouti or silver gene. The horse color calculator reads those hidden genes from the genotypes you enter, so the results show the full range of colors a pairing can produce, including colors neither parent displays.
Bay stallion
Ee
Chestnut mare
ee
There are 4 main groups of users:
The horse coat color calculator covers 10 genes for each parent. Every gene has 2 or 3 genotype options, written with 2 letters: one copy from the horse's sire and one from its dam.
| Gene | Symbol | Genotype options | What the gene does |
|---|---|---|---|
| Extension (Red/Black Factor) | E | EE, Ee, ee | Decides whether the horse makes black pigment. ee horses are red (chestnut). |
| Agouti | A | AA, Aa, aa | Restricts black pigment to the mane, tail and legs, turning black into bay. Visible on black-based horses only. |
| Cream | Cr | nn, Crn, CrCr | Lightens the coat. One copy and two copies give different colors. |
| Dun | D | DD, Dd, dd | Lightens the body and adds a dorsal stripe and leg barring. |
| Silver | Z | ZZ, Zz, zz | Lightens black pigment and turns a black mane and tail flaxen. Has no visible effect on chestnuts. |
| Champagne | Ch | ChCh, Chch, chch | Lightens red and black pigment and gives freckled skin and amber eyes. |
| Gray | G | GG, Gg, gg | Turns the coat progressively white with age. |
| Roan | Rn | RnRn, Rnrn, rnrn | Mixes white hairs through the body while the head and legs stay dark. |
| Tobiano | TO | TOTO, TOto, toto | Adds a white spotting pattern that usually crosses the back. |
| Frame Overo (LWO) | O | On, nn | Adds a frame overo pattern. Two copies cause a fatal condition in foals. |
To predict foal color, enter both parents' genotypes and run the calculation. The process takes 4 steps.
Step 1: Fill in the Sire's Genetics panel. Select the stallion's genotype for each of the 10 genes, from Extension to Frame Overo (LWO).
Step 2: Fill in the Dam's Genetics panel. Select the mare's genotype for the same 10 genes.
Step 3: Press Calculate Foal Colors. The calculator combines both parents' genes.
Step 4: Read the Possible Foal Colors list. Each color name shows the chance of a foal having that color.
The results list gives 3 kinds of information:
| What you see | Meaning |
|---|---|
| Color name | The coat color and pattern a foal with that genotype shows, such as bay roan or palomino tobiano |
| Percentage | The chance that one foal from this breeding has that color |
| Non-viable flag | A genotype that does not produce a living foal, such as 2 frame overo copies |
The list shows only the colors this pairing can produce, so a missing color is a color the pairing cannot produce. Compare the list against your breeding goal: a high percentage for the target color and no non-viable outcome is the strongest pairing.
Every gene field needs a selection. Without a DNA test, choose the genotype the horse's color and pedigree support, and run the calculation more than once to compare scenarios.
| Parent's appearance | Genotypes that fit | What to enter |
|---|---|---|
| Chestnut or sorrel | ee, with any Agouti genotype | ee; test Agouti or run AA, Aa and aa separately |
| Bay | EE or Ee, with AA or Aa | Run EE and Ee to see both outcomes |
| Black | EE or Ee, with aa | aa for Agouti; run EE and Ee |
| Palomino | ee and Crn | ee and Single Cream (Crn) |
| Buckskin | EE or Ee, AA or Aa, and Crn | Single Cream (Crn); test Extension and Agouti |
| Cremello or perlino | CrCr | Double Cream (CrCr) |
| Gray | GG or Gg | Gg, unless the horse has produced only gray foals |
| No white pattern | toto, rnrn, nn | Non-pattern options |
Two runs with different genotypes show the best-case and worst-case odds for an untested horse.
Horse coat color genetics follows Mendelian inheritance: each parent passes 1 of its 2 copies of every gene to the foal, at random, with a 50% chance for each copy. The calculation runs in 4 stages:
Enter parent genotypes. The sire's and dam's selections set the copies each parent can pass on.
Build a Punnett square for each gene. A Punnett square lists the 4 equally likely copy combinations a foal can receive for one gene. Each combination carries a 25% chance.
Combine all genes. The calculator multiplies the chances across the 10 genes to get the chance of every full genotype.
Translate genotype to coat color. Each full genotype becomes a color name, such as bay roan or palomino tobiano. Genotypes that end in the same color are added together.
For a dominant gene such as Dun, Gray, Roan or Tobiano, 1 copy is enough to show the trait. The chance of a foal showing the trait follows this table:
| Sire × Dam | Foal genotypes | Chance the foal shows the trait |
|---|---|---|
| Homozygous (DD) × any | All foals carry at least 1 copy | 100% |
| Heterozygous (Dd) × heterozygous (Dd) | 25% DD, 50% Dd, 25% dd | 75% |
| Heterozygous (Dd) × non-carrier (dd) | 50% Dd, 50% dd | 50% |
| Non-carrier (dd) × non-carrier (dd) | 100% dd | 0% |
Cream follows incomplete dominance: 1 copy and 2 copies produce different colors.
| Sire × Dam | No Cream (nn) | Single Cream (Crn) | Double Cream (CrCr) |
|---|---|---|---|
| nn × nn | 100% | 0% | 0% |
| Crn × nn | 50% | 50% | 0% |
| Crn × Crn | 25% | 50% | 25% |
| CrCr × nn | 0% | 100% | 0% |
| CrCr × Crn | 0% | 50% | 50% |
| CrCr × CrCr | 0% | 0% | 100% |
25% chestnut · 50% palomino · 25% cremello
Single-gene results come in 25% steps. Foal coat color probability across several genes multiplies those steps, so combined percentages can fall between them.
All percentages in the Possible Foal Colors list add up to 100%. Each percentage is the chance for one foal from one breeding. It does not set how many foals of each color a mare will have.
The base color comes from Extension and Agouti. The dilution genes then change that base. This chart shows the standard color names for the 3 base colors.
| Base color | Genotype | + Single Cream | + Double Cream | + Dun | + Champagne | + Silver |
|---|---|---|---|---|---|---|
| Chestnut | ee | Palomino | Cremello | Red dun | Gold champagne | No visible change |
| Bay | E_ A_ | Buckskin | Perlino | Bay dun (classic dun) | Amber champagne | Silver bay |
| Black | E_ aa | Smoky black | Smoky cream | Grullo | Classic champagne | Silver black |
The underscore (_) means the second copy can be either version. E_ covers EE and Ee.
Silver black goes by the name chocolate, and by silver dapple in some breeds. In Australia and New Zealand, the name taffy is common for silver-diluted horses.
Gray, Roan, Tobiano and Frame Overo add to these names. A bay with 1 roan copy is a bay roan. A palomino with 1 tobiano copy is a palomino tobiano. A gray foal is born in its base color and turns gray over its first years of life.
These 6 examples show common breedings. All genes not listed are set to non-carrier (nn, dd, zz, chch, gg, rnrn, toto) for both parents.
The sire is a heterozygous bay (Ee, Aa). The dam is a chestnut (ee, aa).
| Gene | Sire × Dam | Foal odds |
|---|---|---|
| Extension | Ee × ee | 50% Ee, 50% ee |
| Agouti | Aa × aa | 50% Aa, 50% aa |
| Possible foal color | Calculation | Probability |
|---|---|---|
| Bay | 50% black pigment × 50% agouti | 25% |
| Black | 50% black pigment × 50% non-agouti | 25% |
| Chestnut | 50% ee | 50% |
A homozygous black-factor bay stallion (EE) would remove the chestnut outcome entirely.
Both parents are palomino (ee, Crn).
| Possible foal color | Genotype | Probability |
|---|---|---|
| Chestnut | ee nn | 25% |
| Palomino | ee Crn | 50% |
| Cremello | ee CrCr | 25% |
Palomino is a single-cream color. A palomino × palomino breeding produces 3 colors, and only half the foals on average are palomino.
The sire is a cremello (ee, AA, CrCr). The dam is a homozygous black (EE, aa, nn).
| Gene | Sire × Dam | Every foal receives |
|---|---|---|
| Extension | ee × EE | Ee |
| Agouti | AA × aa | Aa |
| Cream | CrCr × nn | Crn |
The result is a 100% buckskin foal. The cremello sire carries agouti hidden under his red base, and the black dam supplies black pigment. Hidden genes produce a color neither parent shows.
Both parents are Ee and Aa.
| Possible foal color | Calculation | Probability |
|---|---|---|
| Bay | 75% × 75% | 56.25% |
| Black | 75% × 25% | 18.75% |
| Chestnut | 25% ee | 25% |
This breeding shows why multi-gene results fall between the 25% steps.
The sire is a chestnut-based gray tobiano (ee, Gg, TOto). The dam is a solid chestnut (ee, gg, toto).
| Possible foal color | Probability |
|---|---|
| Gray tobiano | 25% |
| Gray | 25% |
| Chestnut tobiano | 25% |
| Chestnut | 25% |
Every foal from this pairing is born chestnut-based. The foals listed as gray turn gray as they age.
Both parents are bay frame overo carriers (EE, AA, On).
| Possible foal outcome | Genotype | Probability |
|---|---|---|
| Bay frame overo | On | 50% |
| Solid bay | nn | 25% |
| Non-viable (lethal white) | OO | 25% |
A breeding of 2 frame overo carriers carries a 25% chance of a lethal white foal. The calculator flags this outcome as non-viable. Foals with 2 copies are born white with an intestinal defect and do not survive.
Some breedings fix a color outcome at 100%. The table lists 8 common breeding goals and the pairing that reaches each one.
| Breeding goal | Pairing | Foal result |
|---|---|---|
| 100% palomino | Chestnut (ee, nn) × cremello (ee, CrCr) | Every foal is palomino |
| 100% buckskin | Bay (EE, AA, nn) × cremello (ee, AA, CrCr) | Every foal is buckskin |
| 100% smoky black | Black (EE, aa, nn) × smoky cream (EE, aa, CrCr) | Every foal is smoky black |
| 100% gray | Any horse × homozygous gray (GG) | Every foal turns gray |
| 100% tobiano | Any horse × homozygous tobiano (TOTO) | Every foal is tobiano |
| 100% dun | Any horse × homozygous dun (DD) | Every foal is dun |
| No chestnut foals | Any horse × homozygous black factor (EE) | Every foal has black pigment |
| No lethal white risk | Frame overo carrier (On) × non-carrier (nn) | No foal receives 2 copies |
Enter the pairing in the calculator to confirm the full result. Other genes on either parent, such as Dun or Silver, add their own odds to the list.
There are 4 genes in the calculator with health effects breeders track:
Frame Overo (LWO). Two copies cause lethal white foal syndrome. One copy causes no health problem. Breed carriers only to tested non-carriers.
Silver. Silver is associated with Multiple Congenital Ocular Anomalies (MCOA), an eye condition. Horses with 1 copy have milder signs, usually cysts. Horses with 2 copies show more eye abnormalities.
Gray. Gray horses have a high risk of melanoma as they age. Check gray horses for skin lumps under the tail and around the head.
Double Cream. Cremello, perlino and smoky cream horses have pink skin and blue eyes. Provide shade or sun protection for horses with pink skin.
There are 7 common mistakes that make color predictions wrong:
Guessing genotypes from appearance. A bay can be EE or Ee, and the two give different foal odds. Test Extension and Agouti on stallions and broodmares.
Ignoring Agouti on chestnuts. Chestnut horses carry agouti without showing it. A chestnut mare bred to a black stallion can produce a bay foal.
Missing silver on chestnuts. Silver has no visible effect on red coats. A chestnut can pass silver to a foal, which shows it when the foal has black pigment.
Reading a smoky black as black. One cream copy barely changes a black coat. Test for cream before entering No Cream (nn) on a black horse.
Entering a gray horse's appearance. Gray hides the base color. Enter the base color the horse had at birth, or its DNA results, for Extension and Agouti.
Confusing dun with buckskin. A buckskin has cream and no dorsal stripe. A bay dun has the dun gene and a dorsal stripe. The genes and the foal odds are different.
Treating percentages as guarantees. A 50% chance of a palomino does not mean 1 palomino in every 2 foals. Each foal is a separate draw.
The calculator's results are exact probabilities for the genotypes you enter. There are 5 limits on what the results describe:
The calculator covers 10 genes. It does not include pearl, mushroom, splashed white, sabino, leopard complex (appaloosa patterns), dominant white or brindle.
White markings are not predicted. Face and leg markings depend on several genes, and no simple test predicts them.
Shade modifiers are not included. Sooty, flaxen and dapples change the shade of a color, so 2 foals with the same result can look different.
Linked genes are treated separately. Tobiano and roan sit close together on the same chromosome, so real odds for a horse carrying both can differ from the calculated odds.
Results depend on correct inputs. One wrong genotype changes every percentage.
Use the results to plan a breeding and to compare stallions. Confirm uncertain genotypes with a DNA test before relying on a color outcome. Registry color names differ between breeds, so check the naming rules of your breed association before registering a foal. Use the Contact Us page to report a result or suggest a gene for the calculator.
Enter the sire's and dam's genotypes in the foal color calculator above, press Calculate Foal Colors, and see every possible coat color for the foal with its probability. Compare stallions, test untested genotypes in separate runs, and check frame overo results before booking a breeding.
Calculate Foal Colors