How coat colour is inherited in cats
A kitten’s colour is set by several independent genes, and each kitten receives one copy of every gene from the sire and one from the dam. The dilute gene (d) turns black into blue and red into cream; it is recessive, so a blue kitten from two black parents is possible only if both carry dilute. The agouti gene (A) produces the tabby pattern: two solid parents give only solid kittens, while two tabbies can produce a solid if both are carriers. Mackerel (Mc) is dominant over classic, so two classic tabby parents give only classic kittens. Silver (I) is dominant: a silver or smoke kitten needs at least one silver parent. On a solid cat silver shows as smoke.
Red colour and the kitten’s sex
The orange gene (O) sits on the X chromosome, so males and females inherit colour differently. A male gets his X only from his mother, so a red or cream male can come only from a red, cream or tortie dam, whatever the sire’s colour. A female gets an X from each parent: if one passes the orange gene and the other does not, she will be a tortie. That is why torties (f, g) are almost always female; tortie males are extremely rare, caused by a chromosome anomaly, and are usually sterile.
White, bicolour and van
Dominant white (W) completely masks the real colour: under the white coat the cat carries another genetic colour and passes it on to the kittens. That is why the calculator asks for the colour under the white, which is usually known from the pedigree. A white kitten can only come from a white parent. Blue-eyed white cats are more prone to congenital deafness, so catteries test hearing (BAER test). White spotting (S) is inherited differently: one copy usually gives a bicolour or “with white” (03, 09), two copies a van or harlequin (01, 02). The exact amount of white also depends on modifier genes, so the calculator shows these colours in pairs.
How to use the calculator
For the father and the mother, type the colour in words (“black silver tabby”, “red bicolour”) or the EMS code from the pedigree (“ns 22”, “fs 23 03”) — or just tap one button in each row: coat colour, pattern, whether there is silver and whether there are white patches. All possible kitten colours appear below right away, with percentages and a note on who can have that colour — males, females or both. Breeders can open “For breeders” and note blue, cream, solid or classic tabby ancestors for a more precise result. Your selection is saved in your browser.
EMS colour codes for Maine Coons
n | black |
a | blue |
d | red |
e | cream |
f | black tortie |
g | blue-cream tortie |
w | white |
s | silver (smoke on a solid) |
22 | classic tabby |
23 | mackerel tabby |
24 | spotted tabby |
01 | van |
02 | harlequin |
03 | bicolour |
09 | with white |
For example, MCO ns 22 03 is a black silver classic tabby bicolour Maine Coon.
FAQ
Can two black cats have blue kittens?
Yes, if both parents carry the dilute gene. Then on average one kitten in four will be blue or cream.
Which parent does a kitten inherit red colour from?
A male only from his mother, because the orange gene is on the X chromosome. A female from both parents; if only one passes the orange gene, she will be a tortie.
Can silver parents have non-silver kittens?
Yes, if both parents carry only one copy of the silver gene (one of their own parents was non-silver). Then about one kitten in four will be non-silver.
Can a male cat be tortoiseshell?
Very rarely: it requires two X chromosomes (XXY). Such males are usually sterile, so the calculator does not show tortie males.
Why doesn’t the calculator include chocolate or colourpoint?
The WCF and FIFe Maine Coon standard does not recognise chocolate, cinnamon, lilac or colourpoint, so they are not included.