Baby eye color predictor
Pick each parent's eye colour to see the odds your baby will have brown, green or blue eyes, based on the classic two-gene model of eye colour inheritance.
Hazel counts as green here; grey counts as blue.
How brown-eyed parents can have a blue-eyed baby
Every parent carries two copies of each eye-colour gene and passes one, at random, to each child. In this model, one gene decides brown (B) versus not-brown (b); a second decides green (G) versus blue (b). Brown wins over everything, green wins over blue. Set each parent's hidden copies and watch the odds.
Brown gene Punnett square (each square = 25%)
| BB | Bb |
| bB | bb |
Try two Bb / bb parents: both have brown eyes, yet 1 in 4 children gets bb from both and ends up blue-eyed.
What the model leaves out
Eye colour comes from how much melanin sits in the front layer of the iris. The HERC2/OCA2 region on chromosome 15 accounts for most of the difference between brown and blue, but genome-wide studies (for example Simcoe et al., Science Advances 2021) have linked over 60 genetic variants to eye colour. That's why real families sometimes break the simple rules, and why hazel, grey and amber aren't captured here.
Frequently asked questions
Can two brown-eyed parents have a blue-eyed baby?
Yes. If both parents carry a hidden blue variant alongside their brown one, each child has roughly a 1 in 4 chance of inheriting blue from both. The explainer on this page lets you try it.
Can two blue-eyed parents have a brown-eyed baby?
It's rare but possible. Eye colour is shaped by many genes (at least 16 have been linked to it), so the simple "blue is always recessive" rule taught in school doesn't hold in every family.
When is a baby's eye colour final?
Many babies of European ancestry are born with blue or grey eyes because melanin builds up after birth. Most eye colour changes happen in the first 6–12 months, but it can keep shifting subtly until about age 3. Babies born with brown eyes usually keep them.
How accurate is an eye colour predictor?
It's a rough guide. This calculator uses the classic two-gene model, which explains most brown/green/blue inheritance but not hazel, grey or amber shades, nor the many smaller genetic influences. Treat the percentages as odds, not a promise.