Baby Eye Color Calculator
Predict your baby's eye color based on parent and grandparent genetics using Mendelian inheritance principles.
Selected: Brown
Selected: Brown
Select parent eye colors above to predict your baby's eye color.
Adding grandparent colors improves accuracy.
How to Use This Calculator
Select Mother's Eye Color
Click on the mother's eye color section and choose from brown, blue, green, or hazel. This is the most important input for predicting your baby's eye color.
Select Father's Eye Color
Choose the father's dominant eye color in the same way. The combination of both parents' genetics is key to the prediction.
Add Grandparent Eye Colors (Optional)
For more accurate predictions, you can optionally expand the Advanced Genetics section and add grandparents' eye colors. This helps identify recessive traits.
View Results
The calculator will instantly show the probability percentages for each eye color. The most likely color is highlighted. Remember that genetics is a probability, not a guarantee.
How We Calculate
Eye color inheritance is determined primarily by two genes: OCA2 (which produces brown pigment) and HERC2 (which regulates OCA2 expression). This interaction follows a complex pattern that is often simplified as a dominant/recessive model. Brown eyes are dominant, meaning a baby needs only one brown allele to express brown eyes. Blue eyes are recessive and require two blue alleles. Green and hazel eyes result from intermediate expression of these genes. The prediction model uses simplified Mendelian genetics that accounts for the probability of different genotypes based on parental phenotypes. Research from Stanford University's Department of Genetics shows that while this simplified model cannot predict with 100% certainty due to the complexity of polygenic inheritance, it provides accurate probability estimates for most population groups. Additional factors like ethnic background can influence baseline probabilities, though the calculator uses general population averages. Eye color can take up to 12 months to fully develop in infants as melanin levels increase in the iris. What appears as blue at birth often changes to brown, green, or hazel over the first year of life, which is why newborn predictions may differ from final eye color.
Sources & References
- Stanford University — Genetics of Eye Color (stanford.edu/~sstrohminger/lab)
- Online Mendelian Inheritance in Man (OMIM) — OCA2 Gene Database (omim.org)
- Nature Genetics — Genome-Wide Association Study of Eye Color Inheritance
Data last verified:
Frequently Asked Questions
This calculator uses a simplified Mendelian genetics model and provides probability estimates based on parental eye colors. For most cases, it predicts the correct color outcome with 70-85% accuracy. However, eye color inheritance is complex and involves multiple genes, so the prediction should be viewed as probabilities rather than guarantees. Unexpected results occasionally occur due to rare genetic combinations or recessive traits not visible in parents.
Grandparents' eye colors help identify recessive genes that parents may be carrying but not expressing. For example, two brown-eyed parents could have blue-eyed children if both carry recessive blue alleles inherited from their parents. Including grandparent data helps refine predictions for these hidden genetic traits.
Yes, this is possible if both parents carry a recessive blue eye allele. Brown eyes are dominant, so a parent with brown eyes can carry a hidden blue allele that they inherited from their own parents. If both parents contribute the blue allele to the baby, the baby can have blue eyes despite both parents having brown eyes.
Most babies are born with blue or gray eyes due to low melanin at birth. Eye color typically stabilizes within the first 3-6 months of life, though in some cases it can take up to 12 months for the final color to appear. Melanin, the pigment that gives eyes their color, gradually increases and accumulates in the iris over these months.
Yes, there is always a chance of variation due to the complexity of polygenic inheritance and the influence of ethnic genetic background. The prediction shows the most likely outcomes based on basic Mendelian genetics, but rare genetic combinations can produce unexpected results. Some eye color genes are not yet fully understood by science.
The primary genes are OCA2 and HERC2. OCA2 produces the brown pigment melanin, while HERC2 controls whether OCA2 is turned on or off. Other genes like SLC24A4, TYR, and IRF4 also contribute to eye color variations. This multifactorial inheritance is why blue-eyed children can sometimes be born to brown-eyed parents.
Yes, genetic background influences baseline eye color distribution. For example, blue eyes are more common in Northern European populations, while brown eyes are more common in African, Asian, and Mediterranean populations. The calculator uses general population averages, so individual results may vary based on family ancestry.
Hazel eyes can appear to shift in color as the baby grows due to changes in melanin levels and light reflection patterns in the iris. What appears as hazel in infancy may become more green or more brown over time. This is completely normal and reflects ongoing melanin development.
You can still get a prediction with just your eye color, but accuracy will be reduced. The calculator requires at least the mother's and father's eye colors for the most basic prediction. If you're unsure about eye color classification, you can try different combinations to see the range of possibilities.
Green eyes are not as dominant as brown, but they're not purely recessive either. Green eyes result from a combination of the HERC2 and OCA2 genes, plus other modifying genes. The exact inheritance is complex, but generally green eyes require specific genetic conditions. Two green-eyed parents have a higher chance of green-eyed children than two blue-eyed parents.
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