Rabbit Color Genetics Calculator

About the Rabbit Color Genetics Calculator

Rabbit coat color is determined by five main gene loci: A (agouti), B (brown), C (color/albino series), D (dilute), and E (extension). Each locus has multiple alleles arranged in a dominance hierarchy, and the interaction between all five loci produces the enormous variety of rabbit colors — from jet black to pure white, and everything in between.

Understanding these genetics helps breeders predict offspring colors, plan breeding programs to produce desired colors, and avoid unwittingly producing unshowable colors. The A locus controls whether pigment is banded (agouti) or solid; B determines black vs. chocolate base color; C controls color intensity (including pointed white and albino); D determines normal vs. dilute (blue, lilac); and E controls extension of color across the body.

This calculator predicts the probability of different kit colors from two parents. Enter the known or suspected genotype at each locus for both the sire and dam to see the full Punnett square breakdown. Common colors like REW (ruby-eyed white/albino, cc), black (aaB-C-D-E-), blue (aaB-C-ddE-), and chocolate (aabbC-D-E-) result from specific allele combinations across all five loci.

When This Page Helps

Color genetics predictions help breeders plan matings to produce desired colors, understand why unexpected colors appear, track recessive alleles through generations, and avoid costly surprise litters of unshowable colors.

How to Use the Inputs

1. Select the sire's (father's) genotype at each of the 5 loci
2. Select the dam's (mother's) genotype at each of the 5 loci
3. Use breed presets for common color standards
4. View the predicted kit color probabilities
5. Review the Punnett square breakdown per locus
6. Note: heterozygous carriers can produce unexpected colors

Example Calculation

Tips & Best Practices

• Always track carrier status through pedigrees
• REW (cc) hides ALL other color genes — breed carefully
• If both parents carry the same recessive, 25% of kits will show it
• Test-mating to a homozygous recessive reveals hidden alleles
• Broken (En) is a separate gene system not covered by A/B/C/D/E
• Some colors look identical but have different genotypes (phenocopies)

The Five Color Loci Explained

**A Locus (Agouti):** Controls hair banding. A = agouti (banded, wild pattern), aᵗ = tan (otter pattern), a = self (solid). The agouti bands create the typical "wild rabbit" look with ticked fur. **B Locus (Brown):** B = black pigment, b = chocolate (brown) pigment. Simple dominance. **C Locus (Color):** Most complex with 5 alleles controlling intensity. Full color (C) through chinchilla (removes yellow), sable (light chinchilla), pointed/Himalayan (color on extremities only), to albino (c, no pigment). **D Locus (Dilute):** D = dense/normal, d = dilute. Dilute turns black → blue and chocolate → lilac. Simple recessive. **E Locus (Extension):** Controls how far color extends. Es = steel (darkened agouti), E = normal extension, eⱼ = Japanese (harlequin), e = non-extension (fawn/tort/orange base).

Common Color Genotypes

**Black:** aaB-C-D-E-. **Blue:** aaB-C-ddE-. **Chocolate:** aabbC-D-E-. **Lilac:** aabbC-ddE-. **Chestnut Agouti:** A-B-C-D-E-. **Opal:** A-B-C-ddE-. **Chinchilla:** A-B-cᶜʰᵈ-D-E-. **Siamese Sable:** aa-cᶜʰˡcᶜʰˡ-D-. **Pointed White (Himalayan):** --cʰcʰ-- or --cʰc--. **REW (Albino):** --cc--.

Predicting Kit Colors

Each locus segregates independently (like Mendel's peas). Calculate the probability at each locus separately, then multiply all five probabilities together for the overall color probability. For example: Aa × Aa = 75% A- : 25% aa at the A locus. Bb × Bb = 75% B- : 25% bb at B. The chance of aabb (chocolate self) = 25% × 25% = 6.25% (before considering C, D, E loci).

Frequently Asked Questions

• What is the A (agouti) locus?

  The agouti locus determines hair banding pattern. A (agouti) produces banded hairs with rings of color — this creates the "wild" pattern (like cottontails). aᵗ (tan) produces self-colored top with lighter belly. a (self) produces solid color throughout. Dominance: A > aᵗ > a.

• What does the C locus control?

  The C locus is the most complex — it controls color intensity with 5 alleles: C (full color), cᶜʰᵈ (dark chinchilla — removes yellow/red), cᶜʰˡ (light chinchilla/sable), cʰ (Himalayan/pointed white — color only on extremities), c (REW/albino — no pigment, ruby eyes). Dominance: C > cᶜʰᵈ > cᶜʰˡ > cʰ > c.

• How do I know my rabbit's genotype?

  Visible color (phenotype) reveals dominant alleles, but recessive alleles may be hidden. To determine genotype: know the parents' colors (pedigree), test-breed to a known recessive, or observe offspring from multiple breedings. DNA testing is available but uncommon for rabbits.

• What is a "broken" pattern?

  Broken (En locus) produces white patches mixed with color. EnEn = "Charlie" (mostly white, too much white for show). Enen = broken (ideal show pattern). enen = solid. The En gene is on a separate locus from the A/B/C/D/E system covered in this calculator.

• Why did I get unexpected kit colors?

  Both parents likely carry hidden recessive alleles. A black rabbit may be AaBbCcDdEe — carrying genes for agouti, chocolate, REW, dilute, and non-extension. When bred to another carrier, any combination of these recessives can appear in kits. This is why pedigree knowledge is crucial.

• What causes ruby-eyed white (REW)?

  REW (albino) is homozygous cc at the C locus. This completely prevents pigment production regardless of all other loci. A REW rabbit can carry ANY combination of A, B, D, E genes — they're just hidden. This is why REW × REW always produces REW, but REW × colored can produce many colors if the REW carries hidden alleles.