What this calculator does
Baby eye color probability works out likely eye colors for a baby from both parents’ eye colors, using a simplified genetic model. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
FormulaSimplified 3-allele model (brown dominant over green, green dominant over blue); brown-eyed parents assumed heterozygous brown-green or brown-blue, green-eyed parents assumed green-blue
The inputs explained
| Field | What to enter |
|---|---|
| Parent 1 eye color | Choose from Brown, Green, Blue. |
| Parent 2 eye color | Choose from Brown, Green, Blue. |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with parent 1 eye color
Every other input is held at the calculator’s starting values. Select any row to load that scenario.
How the answer changes with parent 1 eye color
| Parent 1 eye color | Most likely eye color | Possible outcomes | Note |
|---|---|---|---|
| Brown | Brown (33.3%) | 3 | Eye color is polygenic (~16 genes); this simplified model gives a rough estimate only |
| Green | Green (50.0%) | 2 | Eye color is polygenic (~16 genes); this simplified model gives a rough estimate only |
| Blue | Blue (100.0%) | 1 | Eye color is polygenic (~16 genes); this simplified model gives a rough estimate only |