A baby hair color calculator with simple genetics
Will your baby be dark-haired, blond or a redhead? This baby hair color calculator shows the chance of black or dark brown, brown, blond, red and auburn hair from the parents’ natural hair colours, and lets you add the four grandparents to sharpen the guess. It works through every combination of gene copies, like a Punnett square for two genes at once.
It is for fun. Hair colour depends on many genes, and the model here is simplified on purpose, so the result is an entertainment estimate — not a prediction you can rely on and not a genetic test. The calculation runs in your browser and nothing is saved or sent.
How to use the Baby Hair Color Calculator
- Pick the mother’s natural hair color and the father’s natural hair color — the colour before any dye or greying, ideally as a young adult.
- Optionally open Add grandparents and set those you know. Red hair in a grandparent matters most, because the red version of the gene is often hidden.
- Read the most likely colour and the bar for every colour. Change any choice and the results update straight away.
- If a combination is flagged as impossible, that is the simple model’s limit; clear a grandparent to continue.
Baby Hair Color Calculator features
Five outcomes
Black or dark brown, brown, blond, red or strawberry blond, and auburn.
Red hair carriers
Tracks hidden copies of the red version of MC1R, so two dark-haired parents can still have a redhead.
Grandparents
Up to four grandparents narrow down which hidden copies each parent can carry.
Honest limits
Combinations the model cannot explain are flagged, not silently ignored.
No sign-up
Works on any phone or computer, with nothing uploaded.
How the simplified model works
Hair colour comes from two kinds of melanin: eumelanin, which makes hair brown or black, and pheomelanin, which makes it red or golden. The model uses two genes. A dark pigment gene adds eumelanin: two dark copies give black or dark brown hair, one gives brown, and none gives blond. The MC1R gene decides whether pheomelanin takes over: one normal copy is enough for non-red hair, while two red copies give red or strawberry-blond hair — or auburn when the dark pigment is strongest.
Each parent passes one copy of each gene to the baby at random. Because hidden copies cannot be seen, the calculator starts by assuming both versions of each gene are equally common and then uses the parents’ and grandparents’ hair to work out which hidden copies are likely.
| Parents | Most likely | Also possible |
|---|---|---|
| Brown × blond | Brown 44.4% or blond 44.4% | Red 11.1% |
| Red × red | Red 88.9% | Auburn 11.1% |
| Black × dark brown | Black / dark brown 88.9% | Auburn 11.1% |
| Blond × blond | Blond 88.9% | Red 11.1% |
What real hair genetics looks like
MedlinePlus Genetics (US National Library of Medicine) notes that MC1R is the best-understood gene: changes in one copy can give strawberry-blond, auburn or red tones, and changes in both copies usually give very red hair. But at least 21 other genes affect the type and amount of melanin, which is why hair comes in so many shades between blond and black.
The equal-odds starting point is the biggest simplification. Red hair is rare in most of the world, and in India and much of Asia and Africa almost everyone carries only dark-pigment versions, so the real chances there are far more strongly dark than this calculator shows.
Baby hair changes
Newborn hair often falls out in the first months and grows back a different shade. Especially in families of European descent, blond toddlers often become light-brown or brown-haired children and teenagers, probably because of hormonal changes. So a fair-haired baby is a poor guide to adult hair colour.
For other family guesses, try the baby eye color calculator, the child height predictor or browse ideas with the baby name generator.
Baby Hair Color Calculator FAQ
Can two dark-haired parents have a red-haired baby?
Yes. If both carry a hidden red copy of MC1R, each baby has about a 1 in 4 chance of two red copies. A red-haired grandparent on each side makes that more likely.
How accurate is a hair color calculator for a baby?
It is a rough, fun estimate. It follows a two-gene model; real hair colour depends on many genes and on how common each gene version is in your family background.
Is blond hair recessive?
In this model blond means no dark-pigment copies, so two blond parents mostly have blond children. In reality several genes are involved, and blond children often darken with age.
Why should I use natural hair color?
Dye, sun lightening and greying do not change the genes a parent passes on. Use the colour as a child or young adult.
Does the hair color calculator use grandparents?
Yes, optionally. Grandparents’ colours change which hidden gene copies each parent probably carries, especially for red hair.
Is this a genetic or medical test?
No. It is for entertainment only and cannot tell you anything about health.