Baby Eye Color Calculator

How this is calculated

This tool uses a simplified probability table based on the classic idea that brown eye color is broadly dominant over blue, with hazel and green sitting in between. Each parent-color combination (brown + blue, hazel + hazel, and so on) maps to a rough set of odds for brown, hazel/green, or blue/gray in the baby, and grandparent colors nudge those odds slightly since recessive genes can skip a generation.

It's important to be upfront about what this is: a fun, simplified estimate, not a real genetic prediction. The old single-gene, brown-is-dominant model taught in introductory biology is a big oversimplification of how eye color actually works. In reality, eye color is influenced by many genes — two genes near each other on chromosome 15 (OCA2 and HERC2) have the largest effect, but researchers have identified well over a dozen other genes that each contribute a smaller piece, which is part of why eye color can vary so much even between siblings with the same two parents.

The percentages shown are also a coarse three-way split — brown, hazel/green, and blue/gray — rather than a prediction of an exact shade. Real eye color spans a continuum from very dark brown through amber, hazel, green, gray and pale blue, shaped by how much and what type of pigment ends up in the iris, which this simplified model can't capture.

Common edge cases and things to know

Many babies are born with eyes that look blue or gray simply because melanin (the pigment that darkens eye color) hasn't fully developed yet — their true, longer-term eye color often isn't clear until somewhere between 6 and 12 months, and can keep shifting subtly for a couple of years after that.

Because so many genes are involved, outcomes that seem surprising do happen — two brown-eyed parents can have a blue-eyed baby, and two blue-eyed parents can (less commonly) have a brown-eyed one, if each parent is silently carrying a recessive variant. Grandparent colors are only a mild signal here, not a strong predictor, and eye color in general exists on a wide continuous spectrum rather than neatly sorting into just four buckets.

Eye color also isn't fixed the moment a baby is born, so don't be surprised if this calculator's estimate and your baby's actual eye color at six months look different from what they looked like on day one. Ethnic background also shapes the starting odds in ways this simplified four-color model doesn't fully account for, since population-level eye color distributions vary widely around the world.

Sources

For general, reader-friendly background on newborn development, including how a baby's eye color can continue to change in the first year, see HealthyChildren.org (from the American Academy of Pediatrics) and Mayo Clinic.