Predict what hair color your baby could have. Select each parent's hair-color alleles to generate a live Punnett square showing the odds of black, brown, red and blonde hair. (Educational single-gene model — real hair color is polygenic.)
Educational tool. Hair color is polygenic (MC1R, HERC2, and many others) and is not determined by a single gene — use this calculator to learn Mendelian inheritance, not for medical prediction.
Simplified dominance hierarchy:
K Black — most dominantN Brown — dominant over red & blondeR Red — dominant over blonde onlyL Blonde — most recessiveThe most dominant allele present determines the visible hair color in this model.
Red and blonde alleles are recessive. Two brown-haired parents who each secretly carry L or R can have a blonde or red-haired child — a 25% chance when both are carriers.
This is the same hidden-carrier logic that surprises families with eye color.
KK × LL = 100% black (all carriers of blonde)NL × NL = 75% brown, 25% blondeRL × RL = 75% red, 25% blondeNR × NR = 75% brown, 25% redReal hair color is polygenic. MC1R controls red pigment, while genes like HERC2, OCA2, and TYR influence how dark hair is. Shades also darken with age.
This single-gene model is a teaching aid for Mendelian ratios, not a clinical predictor.