Calculator
Genetic Traits Probability Calculator
Eye Color
🧬 Educational tool: This calculator uses simplified Mendelian genetics models. Real inheritance involves many genes (polygenic), epigenetics, and environmental factors. Results are theoretical probabilities, not predictions.
👁️ Child Probabilities
Brown55.0%
Green15.0%
Blue22.5%
Hazel7.5%
🟤 Brown
55.0%
🟢 Green
15.0%
🔵 Blue
22.5%
🟡 Hazel
7.5%
How It Works
Eye color is modeled using two genes (OCA2/HERC2 + GEY). Brown is dominant over green and blue. Green is dominant over blue. Two copies of recessive alleles needed for lighter colors.
Combined Summary
👁️Eye Color🟤 Brown: 55.0%🔵 Blue: 22.5%🟢 Green: 15.0%🟡 Hazel: 7.5%
💇Hair Color🟫 Brown: 40.4%🟨 Blonde: 40.4%⬛ Black: 11.8%🟥 Red: 7.5%
🩸Blood TypeType AB: 33.1%Type A: 24.4%Type B: 24.4%Type O: 18.1%Rh+: 67.5% / Rh−: 32.5%
Model: Simplified Mendelian genetics · Eye: OCA2+GEY 2-gene model · Hair: MC1R carrier model · Blood: ABO tri-allelic + Rh bi-allelic
Frequently Asked Questions
What is a Punnett square?
A Punnett square is a grid used to predict the probability of offspring inheriting specific traits. The parent alleles are placed on two axes and all combinations are listed in the cells. It shows possible genotypes and their statistical likelihood.
What is the difference between dominant and recessive traits?
A dominant allele (typically written as a capital letter, e.g. B) masks the recessive allele when present. A recessive trait (written as lowercase, e.g. b) only appears when two copies are inherited — one from each parent. Brown eye color is usually dominant over blue.
Can genetics predict exact traits in children?
No. Genetics gives probabilities, not certainties. Most human traits are polygenic (influenced by many genes simultaneously), not single-gene. Environmental factors further complicate prediction. The Punnett square model applies to simplified single-gene trait analysis.