Eye color calculator
Select both parents' eye colors to see the probability of each eye color for your child, based on the HERC2 and OCA2 gene model.
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Build a full family pedigree and see which inheritance patterns fit your family history.
Open the pedigree toolHow the eye color calculator works
The eye color calculator predicts the likelihood of a child having blue, green, or brown eyes. You select the eye colors of the parents and grandparents. The calculator then uses a genetic model to output the percentage chances for each potential eye color.
The science behind eye color genetics
Eye color genetics is more complex than the simple Punnett square taught in high school biology. It relies on multiple genes, but two genes have the biggest impact. The first major gene is OCA2. This gene controls the amount of melanin produced in the iris. Melanin is the same brown pigment that determines skin color. A mutation in the DNA right next to OCA2, in a gene called HERC2, controls whether OCA2 works at all. This is called epistasis. If both copies of HERC2 are broken, OCA2 shuts down completely. No melanin is produced, and light scatters in the eye to look blue. If OCA2 works normally, the eye produces melanin and looks brown.
The second gene, known as GEY, acts as a switch for green. Green happens when a small amount of melanin is present in the front of the iris, combining with the blue light scattering to create a green appearance. Brown is dominant because a single working copy of the HERC2 or OCA2 genes produces enough melanin to make the eye look brown. Blue is recessive because both copies of HERC2 must carry the mutation to turn off melanin production entirely. Green is intermediate. A child needs two non-working HERC2 copies to eliminate the brown pigment, but also needs the working green variant of the GEY gene. If the child gets two blue copies and no green gene, they will have blue eyes. If they get two blue copies and a green gene, they will have green eyes. This is why asking for grandparent data improves the prediction. Grandparents reveal if the parents carry hidden blue or green genes.
What the calculator leaves out
This calculator uses a simplified two-gene model. In reality, eye color is polygenic, meaning dozens of other genes influence the exact shade. Because of this, the tool is often inaccurate for predicting intermediate colors like hazel or amber. Hazel eyes happen when melanin is distributed unevenly, and amber eyes come from a different type of pigment called lipochrome. The calculator provides a solid baseline probability for blue, green, and brown, but it cannot predict the exact hex code of a human iris.
Frequently asked questions
What eye color will my baby have?
A baby's eye color depends on the genes they inherit from both parents. Brown is dominant over green and blue, and green is dominant over blue. If both parents have brown eyes, the baby will likely have brown eyes, but they can have blue or green if the parents carry those hidden genes.
Can two blue-eyed parents have a brown-eyed child?
In standard Mendelian genetics, no. Because blue eyes are recessive, two blue-eyed parents can only pass on blue genes. However, eye color is polygenic. A rare mutation or an unrecognized ancestry can rarely cause a blue-eyed couple to have a brown-eyed child, but this is highly unusual.
Can two brown-eyed parents have a blue-eyed child?
Yes. Brown is dominant, but a brown-eyed parent can carry a hidden blue gene. If both parents carry the blue gene, there is a 25 percent chance their child will inherit both blue genes and have blue eyes. This is a common occurrence in genetics.
Why is green the rarest eye color?
Green is the rarest eye color because it requires a specific genetic combination. A person needs two copies of the recessive blue gene to eliminate brown melanin, plus a specific variant in a separate gene that produces a yellow pigment. These two factors combined make green eyes statistically uncommon.