Baby Eye Color Calculator — Genetics Probability Predictor
Select both parents' eye colors and see the approximate probability that your baby will have brown, green/hazel, or blue/gray eyes — based on a simplified two-gene Mendelian genetics model.
Parent 1 eye color
Parent 2 eye color
How does this calculator work?
Baby eye color is predicted by a simplified 2-gene Mendelian model: brown is dominant, green is intermediate, blue requires two recessive copies. Two blue-eyed parents give ~100% blue; two brown-eyed parents give ~75% brown, ~19% green, ~6% blue. Predictions are population averages — real genetics involves many more genes.
Formula
How this is calculated
Eye color is influenced by dozens of genes, but two on chromosome 15 — OCA2 and its regulator HERC2 — account for most common variation. In the standard simplified model, brown (B) is dominant over non-brown (b), and green/hazel (G) is dominant over blue (g). Brown overrides all others; green overrides only blue; blue requires no dominant alleles. Each parent passes one allele at each gene to the child, and the Punnett-square calculation gives probabilities for each combination.
The lookup table averages over all realistic genotype pairings for each observable eye color: for example, two brown-eyed parents might both be BB, Bb, or carry a green allele, so the 75% / 19% / 6% brown/green/blue split is a weighted population average rather than a deterministic Mendelian ratio from a single known cross.
Real eye color is a continuous trait influenced by additional genes (TYRP1, SLC24A4, IRF4, and others), UV exposure and ageing. The three-category simplification overestimates certainty, especially for intermediate shades like hazel and amber. Babies often start with blue-gray eyes at birth because iris melanin has not yet accumulated; final color is usually set by 9–18 months.
Frequently asked questions
Very rarely — the standard two-gene model predicts essentially 0%, but uncommon mutations in modifier genes can occasionally produce unexpected outcomes. Two blue-eyed parents have an overwhelming probability (>99%) of a blue or gray-eyed child.
Iris melanin (pigment) has not yet accumulated at birth, so most babies — regardless of eventual adult color — start with blue-gray eyes. Melanin production is triggered by light exposure after birth; final eye color is usually visible by 9–18 months.
These are statistical probabilities for a population, not guaranteed outcomes. Real eye color involves many more genes and is a continuous trait. The calculator is most reliable for the blue–blue (nearly 100% blue) and brown–brown (likely brown) cases; hazel and intermediate cases are less predictable.
TG we-Calculate Editorial Team. (2026). Baby Eye Color Calculator — Genetics Probability Predictor [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/baby-eye-color-calculator
TG we-Calculate Editorial Team. "Baby Eye Color Calculator — Genetics Probability Predictor." TG we-Calculate. 2026. https://we-calculate.com/calculator/baby-eye-color-calculator.
TG we-Calculate Editorial Team, "Baby Eye Color Calculator — Genetics Probability Predictor," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/baby-eye-color-calculator
@misc{wecalculate_baby_eye_color_calculator, title = {Baby Eye Color Calculator — Genetics Probability Predictor}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/baby-eye-color-calculator}}, year = {2026}, note = {TG we-Calculate} }
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