Last updated: June 25, 2026
Rabbit Color Calculator
Creators
Dharmendra SinghReviewers
Creators
Dharmendra SinghReviewers
Quick Answer
The Rabbit Color Calculator predicts litter coat-colour probabilities from two parent genotypes across the five rabbit colour loci: A (agouti/self), B (black/chocolate), C (colour/albino), D (dense/dilute), and E (extension/non-extension). It crosses each locus independently, combines them, and applies epistasis rules (e.g. cc albino masks all colour) to report the most likely colour, a full probability breakdown, and the chance of a ruby-eyed white offspring. Genotypes are entered as 10-letter strings with uppercase for dominant and lowercase for recessive alleles.
Rabbit coat colour is set by five genes: A for agouti, B for black, C for colour, D for density, and E for extension. Enter both parents' genotypes and the calculator predicts the probability of each offspring colour, such as black, blue, chestnut agouti, or ruby-eyed white.
Key Takeaways
- Rabbit coat colour is controlled mainly by five gene loci: A (agouti), B (black), C (colour), D (density), and E (extension)
- Each locus is crossed independently, then combined and resolved with epistasis rules to name the colour
- cc (albino) masks everything to produce a ruby-eyed white rabbit no matter the other genes
- The dilute gene (dd) turns black to blue, chocolate to lilac, and chestnut agouti to opal
- Predicted percentages are long-run averages — a small litter can differ from the expected ratios
Creators
Dharmendra SinghReviewers
Creators
Dharmendra SinghReviewers
Formula
P(colour) = product of per-locus genotype probabilities across the A, B, C, D, E loci
Where:
- A=Agouti locus (A agouti dominant over a self)
- B=Black locus (B black dominant over b chocolate)
- C=Colour locus (C colour dominant over c albino)
- D=Density locus (D dense dominant over d dilute)
- E=Extension locus (E full dominant over e non-extension)
Worked Examples
Two black carriers of the agouti gene
Both parents look black but each carries one agouti allele (Aa) at the A locus.
- 1A locus: Aa × Aa gives 3/4 agouti (A_) and 1/4 self (aa)
- 2B, C, D, E loci are all homozygous dominant, so no variation there
- 3Agouti + B_ + C_ + D_ + E_ = Chestnut Agouti (Castor)
- 4Self (aa) + same = Black
- 5Result: 75% Chestnut Agouti, 25% Black
Two black rabbits carrying albino
Both parents are black selfs but each carries one albino allele (Cc).
- 1C locus: Cc × Cc gives 1/4 cc (albino) and 3/4 coloured
- 2cc offspring are Ruby-Eyed White regardless of other genes
- 3Coloured offspring are all Black (aa, B_, D_, E_)
- 4Result: 75% Black, 25% Ruby-Eyed White
Introduction
The Rabbit Color Calculator predicts the coat-colour probabilities of a litter from the two parents' genotypes. Rabbit colour is controlled by five main gene loci — A (agouti), B (black/brown), C (colour/albino), D (density/dilution) and E (extension). Enter each parent's genotype as a 10-letter string (uppercase = dominant, lowercase = recessive) and the calculator crosses every locus, combines them, and reports the chance of each possible colour — from black and chestnut agouti to blue, chocolate, lilac, and ruby-eyed white. It's a multi-gene extension of a Punnett square; for trait probability basics see our allele frequency calculator.
How the Rabbit Color Calculator Works
Each of the five colour loci is inherited independently, so the calculator first works out the genotype probabilities at each locus (a simple monohybrid cross), then multiplies the loci together to find the chance of every possible colour combination. Finally it applies the rules of epistasis — how genes mask one another — to turn each genotype into an actual coat colour.
Parse both parents' genotypes into five allele pairs (A, B, C, D, E)
Cross each locus separately to get dominant vs recessive probabilities
Combine all five loci (they assort independently)
Apply epistasis rules to name the resulting coat colour
Sum the probabilities for each distinct colour
If you only know the parents' colours, not their full genotypes, assume homozygous dominant unless you know a recessive trait (like a dilute or albino relative) is being carried.
The Five Colour Genes (A B C D E)
Rabbit colour genetics is built on five primary loci. Knowing what each one does is the key to reading a genotype string.
| Locus | Dominant | Recessive | Effect |
|---|---|---|---|
| A — Agouti | A (agouti) | a (self) | Banded vs solid-coloured hair shafts |
| B — Black | B (black) | b (chocolate) | Black vs brown pigment |
| C — Colour | C (full colour) | c (albino) | cc removes all pigment (white) |
| D — Density | D (dense) | d (dilute) | Full vs washed-out colour (black to blue) |
| E — Extension | E (extension) | e (non-extension) | Black pigment vs red/yellow coat |
There are more alleles in real rabbits (e.g. the C and E loci have several), but these dominant/recessive pairs cover the vast majority of pet and show colours.
How Genes Mask Each Other (Epistasis)
Coat colour is not just a sum of genes — some loci override others. Understanding this order is what separates a genotype from a phenotype.
cc (albino) is fully epistatic: a cc rabbit is white no matter what the other genes say
ee (non-extension) hides black pigment, producing red, orange, fawn, or tortoiseshell
A_ (agouti) gives banded hairs (chestnut, opal); aa gives a solid 'self' colour
bb turns black pigment to chocolate; dd dilutes it (black to blue, chocolate to lilac)
The dilute of chestnut agouti is opal; the dilute of chocolate agouti is lilac agouti
Common Colour Genotypes
Here are the genotypes behind some of the most common self and agouti rabbit colours (showing the homozygous form).
| Colour | Genotype | Series |
|---|---|---|
| Black | aaBBCCDDEE | Self |
| Blue | aaBBCCddEE | Self (dilute) |
| Chocolate | aabbCCDDEE | Self |
| Lilac | aabbCCddEE | Self (dilute) |
| Chestnut Agouti (Castor) | AABBCCDDEE | Agouti |
| Opal | AABBCCddEE | Agouti (dilute) |
| Ruby-Eyed White | aaBBccDDEE | Albino |
A rabbit can carry recessive genes it doesn't show. A black rabbit written aaBbCcDdEe carries chocolate, albino, and dilute — and can surprise you in a litter.
Using Your Results for Breeding
The calculator's probabilities are statistical expectations across many kits — an individual litter can differ, especially small ones.
Percentages are long-run averages; a 25% colour may not appear in a litter of 4
Surprise colours reveal hidden recessive genes in a parent
To produce a recessive colour reliably, breed two carriers or two showing the trait
Test-mating to a known recessive animal reveals what a parent carries
Always prioritise health and temperament over colour in any breeding plan
Coat colour has no effect on a rabbit's health. Breed responsibly and never breed solely for a rare colour at the expense of welfare.
Key Terms Glossary
Common terms in rabbit colour genetics.
| Term | Definition |
|---|---|
| Genotype | The genetic make-up (e.g. AaBbCcDdEe) |
| Phenotype | The visible coat colour the genotype produces |
| Locus | A specific gene's position (A, B, C, D or E) |
| Allele | One version of a gene (e.g. B or b) |
| Dominant | An allele that shows when one copy is present (uppercase) |
| Recessive | An allele that shows only when homozygous (lowercase) |
| Epistasis | When one gene masks the effect of another |
| Self | A solid, single-coloured coat (aa) |
| Agouti | A banded-hair coat like wild rabbits (A_) |
Quick Reference Card
Rabbit Color Genetics — Quick Reference
Quick reference • Rabbit Color Calculator
Cross each of the A, B, C, D, E loci, combine, then apply epistasisValid range: Genotype = 10 letters in A,B,C,D,E order (uppercase dominant, lowercase recessive)
Common Values
⚠ Watch Out
- •Percentages are averages — small litters can differ
- •cc (albino) overrides every other colour gene
- •Hidden recessives can produce surprise colours
Pro Tips
- →Write carried recessives explicitly, e.g. aaBbCcDdEe
- →Assume homozygous dominant only when no recessive is known
- →Breed two carriers to reliably get a recessive colour
FAQs
How is rabbit coat colour inherited?
Rabbit colour is controlled mainly by five gene loci — A (agouti), B (black/brown), C (colour/albino), D (density/dilution) and E (extension). Each parent passes one allele per locus to the offspring. The combination of all five, plus epistasis (genes masking each other), determines the visible coat colour.
What do the letters A, B, C, D, E mean?
They are the five primary colour genes. A controls agouti (banded) versus self (solid) coats; B controls black versus chocolate pigment; C controls full colour versus albino; D controls dense versus dilute colour; and E controls whether black pigment extends across the coat or is replaced by red/yellow.
How do I write a rabbit's genotype?
Use 10 letters in A, B, C, D, E order, with an uppercase letter for the dominant allele and lowercase for the recessive. For example, aaBBCCDDEE is a black self rabbit and AaBbCcDdEe is a chestnut agouti carrying self, chocolate, albino, and dilute.
Why did my rabbits produce a colour neither parent has?
Because rabbits can carry recessive genes they don't visibly show. If both parents secretly carry the same recessive allele (e.g. dilute, chocolate, or albino), about a quarter of the litter can express that hidden colour even though neither parent does.
What is a ruby-eyed white rabbit?
A ruby-eyed white (REW) is a true albino. The cc genotype at the C locus removes all pigment, so the rabbit is pure white with pink/ruby eyes regardless of what genes it carries at the other four loci. Two REW parents always produce REW offspring.
What is the difference between black and chestnut agouti?
Both have black pigment, but the A locus differs. A self (aa) rabbit is solid black, while an agouti (A_) rabbit has banded hair shafts that produce the wild-type chestnut agouti (castor) colour with a lighter undercoat and ticking.
What does the dilute gene do?
The recessive dilute allele (dd) lightens the coat: black becomes blue, chocolate becomes lilac, and chestnut agouti becomes opal. A rabbit must inherit dd (one dilute allele from each parent) to show a dilute colour.
Are the calculator's percentages guaranteed for my litter?
No — they are statistical expectations over many offspring. A predicted 25% colour might not appear at all in a small litter, or might appear more often, due to chance. The more kits born across multiple litters, the closer the real ratios get to the predictions.
Can I use this calculator if I only know the parents' colours?
Yes, but you'll get the most accurate prediction if you know the full genotypes. If you only know colours, assume each locus is homozygous dominant unless you have evidence (such as a dilute or albino relative) that a recessive allele is being carried.
Is this rabbit color calculator free?
Yes, the Rabbit Color Calculator is completely free with no registration required. Enter the sire and dam genotypes to instantly see the most likely colour, the full probability breakdown, and the chance of a white offspring.