Just for fun
Baby Eye Colour Predictor
A simplified genetic probability chart for your baby’s likely eye colour. Enter both parents’ eye colours (and optionally grandparents for more accuracy) — we’ll return a probability breakdown across five colours.
Add grandparents for more accuracy (optional)
Your data stays in your browser. Sakina does not store any inputs.
Eye colour genetics, simplified
Eye colour is determined by multiple genes — most importantly OCA2 and HERC2 on chromosome 15. The old “brown dominates blue” rule is roughly true but incomplete; green, hazel and grey come from different combinations of melanin production and light scattering.
When eye colour settles
Most babies are born with slate-blue or grey eyes because melanin production in the iris develops gradually after birth. True eye colour usually settles between 6 and 12 months, though some subtle changes can continue up to 3 years.
Can two blue-eyed parents have a brown-eyed baby?
Rarely — but yes. Because multiple genes interact, unusual combinations can produce outcomes that defy the simple dominant/recessive model. Adding grandparent data to this calculator improves accuracy by hinting at hidden recessive alleles.
Heterochromia
About 1% of people have two different-coloured eyes (complete heterochromia) or different colours within the same iris (sectoral). Usually harmless and genetic, but any sudden change in eye colour during childhood should be evaluated by an optometrist.
Frequently asked questions
How accurate is this predictor?
It applies a simplified two-gene model and is accurate roughly 70–85% of the time for common combinations. Rare outcomes can and do happen.
Why do grandparents affect the result?
They reveal hidden recessive alleles — a brown-eyed parent with one blue-eyed parent carries a blue allele with 50% probability.
Can eye colour change after 12 months?
Subtle shifts can occur into early childhood, but dramatic changes are rare after 9–12 months.
Does sunlight change eye colour?
UV exposure does not permanently change eye colour, though it can slightly darken the iris in early childhood.
Is this medically accurate?
No — this is a fun calculator. True genetic testing (23andMe and similar) gives a more sophisticated estimate, but even that is probabilistic.
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Calculations based on standard obstetric formulas and WHO guidance. For medical decisions, always consult your doctor or midwife.