Team
biology

Rabbit Color Calculator

Rabbit coat color results from the interplay of multiple genes inherited from both parents. Breeders, geneticists, and rabbit enthusiasts use genetic principles to forecast litter colors before breeding occurs. This calculator accepts either direct color selections from a reference library of 121 recognized colors, or manual gene notation—allowing you to model crosses, verify pedigree expectations, and understand the inheritance of dominant and recessive traits across five core loci plus optional modifiers.

Last updated:

Creators Adena Benn, BSc
Reviewers Anna Pawlik and Bogna Szyk
6,856 people find this calculator helpful

Understanding Rabbit Coat Genetics

Rabbit fur coloration is governed by two copies of each gene: one inherited from the sire and one from the dam. Dominant alleles mask recessive ones when paired together, so a rabbit may carry genes not visible in its phenotype. Five primary gene loci account for most color variation in domestic rabbits:

  • A locus (Color pattern): Controls whether hair is banded, shows tan markings, or appears solid.
  • B locus (Pigment hue): Determines black versus brown eumelanin production.
  • C locus (Pigment deposition): Regulates the amount and distribution of color, ranging from full color to albino variants.
  • D locus (Density): Produces full-intensity or diluted pigment expression.
  • E locus (Extension): Controls how far dark pigment extends into the guard hairs.

Additionally, modifying genes such as steel, broken pattern, Vienna, Dutch, silvering, wideband, and lutino create specialized patterns and phenotypes recognized by breed standards.

Mendelian Inheritance and Punnett Squares

When crossing two rabbits, each parent passes one allele at each locus to offspring. With two alleles per locus, simple monohybrid crosses yield predictable ratios. For a single gene with dominant (A) and recessive (a) alleles, an Aa × Aa cross produces:

AA : Aa : aa = 1 : 2 : 1

Phenotypic ratio = 3 (dominant) : 1 (recessive)

  • AA — Homozygous dominant genotype; expresses dominant phenotype
  • Aa — Heterozygous genotype; expresses dominant phenotype due to dominance
  • aa — Homozygous recessive genotype; expresses recessive phenotype
  • Dominant allele — Capital letter (e.g., A); masks recessive when present
  • Recessive allele — Lowercase letter (e.g., a); visible only in homozygous pairs

Five Core Genes and Their Alleles

Each locus has multiple alleles listed in order of dominance. The calculator uses a standardized notation:

  • A locus: A (banded) > at (tan) > a (solid)
  • B locus: B (black) > b (brown)
  • C locus: C (full color) > cchd (chinchilla) > cchl (sable) > ch (Himalayan) > c (albino/red-eyed white)
  • D locus: D (dense) > d (dilute)
  • E locus: E (full extension) > e (non-extension)

A rabbit's phenotype reflects the highest-ranking alleles present at each locus. For example, a rabbit carrying B and b will appear black, while bb rabbits express brown regardless of other genes.

Input Modes: Color Selection vs. Gene Notation

The calculator offers two workflows:

  • Color mode: Select from established color families (full color, chinchilla, seal, sable, Himalayan, red-eyed white) and choose a specific rabbit color by name. The tool auto-populates the underlying genotypes based on the color standard.
  • Gene mode: Manually enter alleles for each locus using standard notation (e.g., AABbCcDdEe). This method suits advanced breeders who know pedigrees or wish to model hypothetical crosses.

When optional modifiers are enabled, you can also specify steel, broken, Vienna, Dutch, silvering, wideband, or lutino genes—or mark them as unknown if uncertain.

Practical Tips for Predicting Offspring Colors

Even experienced breeders encounter surprises in litter phenotypes. Keep these considerations in mind:

  1. Carriers Mask Recessive Traits — A rabbit may carry recessive alleles without displaying them. Two heterozygous parents (Aa × Aa) can produce unexpected homozygous recessive offspring (aa). Always verify parental genotypes through pedigree or genetic testing before predicting rare colors.
  2. C Locus Epistasis in Himalayan and Albino Rabbits — The c locus is particularly complex because certain alleles (especially c and c<sup>h</sup>) suppress all color pigmentation in the coat or eyes. A rabbit homozygous for c will always appear albino, regardless of its A, B, D, or E genotypes.
  3. Modifying Genes Require Explicit Selection — Steel, broken, Vienna, Dutch, silvering, wideband, and lutino genes operate independently. Unselecting these options from your input will exclude them from predictions, even if parents carry them. For accurate results, enable all modifiers present in your breeding stock.
  4. Multiple Offspring Inherit Differently — Predicted percentages describe the statistical probability across many litters. A single cross may produce no rabbits of a given color type even when the calculator forecasts a 25% chance, due to random assortment of alleles.

Frequently Asked Questions

How do rabbits perceive color compared to humans?

Rabbits are dichromats, perceiving only two color channels—blue and yellow—whereas humans possess trichromatic vision and see red, green, and blue. This dichromatic vision evolved to enhance detection of movement and low-light conditions. As a result, rabbits struggle to distinguish red tones and instead perceive red objects as brownish or dark. This has no bearing on coat color genetics, but explains why rabbits may respond differently to colored lighting in captive environments.

What does the C locus control in Himalayan rabbits?

The C locus determines pigment deposition and concentration. Himalayan rabbits carry the c<sup>h</sup> allele, which produces colored markings only on cooler body regions (ears, nose, feet, tail) while the core body remains pale. This temperature-sensitive expression differs from full-color (C) and other variants like chinchilla (c<sup>chd</sup>) or sable (c<sup>chl</sup>). The c allele (albino) completely suppresses pigment and creates red-eyed whites. Dominance order at this locus significantly shifts phenotype.

Why might two brown-colored parents produce black offspring?

A brown rabbit has genotype <code>bb</code> at the B locus. Both parents must carry <code>bb</code> to appear brown. However, if one or both parents are carriers for steel or other pattern modifiers that interact with pigmentation, or if the breeder misidentified coat color, unexpected results occur. More commonly, records errors or incorrect parentage are to blame. Using the gene-input mode with verified genotypes prevents this confusion.

Can I predict exact litter size or sex ratio with this calculator?

No. The calculator predicts only coat color genotype and phenotype probabilities. It does not forecast litter size, sex ratios, or viability. Litter size depends on the dam's age, health, nutrition, and genetics—factors unrelated to color. For a complete breeding assessment, consult veterinary and animal husbandry resources in addition to genetic analysis.

What is the probability of producing an aa offspring from two Aa parents?

Exactly 25%. A Punnett square for Aa × Aa shows four equally probable outcomes: AA (25%), Aa (50%), and aa (25%). The recessive phenotype appears in one of four boxes. While a small litter may contain zero aa rabbits by chance, the underlying probability remains constant. This principle applies to any single locus—scale it up across five genes and multiple loci to see why color prediction requires a calculator.

Should I use color mode or gene mode if I don't know my rabbit's exact genotype?

Start with color mode and select the closest matching color from the reference library. The calculator infers the most likely genotype for that color. If your rabbit displays unusual markings or you suspect it carries hidden recessive genes, switch to gene mode and mark uncertain loci as 'unknown'—some calculators will show a range of possible outcomes. For breeding decisions, genetic testing or a pedigree review provides certainty beyond visual assessment.

biology
VPD Calculator (Vapor Pressure Deficit)
biology
Sod Calculator

More biology calculators (see all)

Bulb Spacing Calculator Animal Mortality Rate Calculator GDU Calculator Dog Water Intake Calculator Grain Conversion Calculator Dog Age Calculator Lawn Mowing Cost Calculator Cat Calorie Calculator