Baby Hair Color Calculator: How Hair Genetics Work

The Genetics of Hair Color and Pigment Types

Hair color is governed by two forms of melanin found in the hair cortex: eumelanin and pheomelanin. Eumelanin produces black and brown shades, while pheomelanin produces yellow, blonde, and reddish tones. Dark hair alleles are genetically dominant over lighter alleles. If a child inherits an active eumelanin gene from either parent, that child will typically develop darker hair than a child who inherits inactive alleles.

Red hair follows distinct genetic rules governed primarily by the MC1R gene on chromosome 16. Red hair is an autosomal recessive trait. To produce a red-haired baby, both parents must carry at least one mutated copy of the MC1R gene. Even if neither parent has red hair themselves, two brown-haired carriers have a one-in-four chance of having a child with vibrant copper or strawberry-blonde hair.

Is Curly Hair Genetic?

Hair texture is also an inherited physical characteristic, but it does not follow simple dominant-recessive rules. Curly hair is often described as dominant over straight hair, but it actually exhibits incomplete dominance. When one parent passes down a curly-hair allele and the other passes down a straight-hair allele, the child frequently develops wavy hair, which represents an intermediate physical expression between both parents.

Follicle structure dictates texture on a microscopic level. Round follicles produce straight hair strands that emerge perpendicular to the scalp, whereas oval or asymmetrical follicles produce curved strands that twist as they grow. Multiple genetic loci regulate follicle geometry, so curl patterns can vary significantly between siblings raised in the exact same household.

Newborn Hair Changes and Exploring Outcomes

The hair your baby is born with is rarely permanent. Many newborns lose their initial hair, called lanugo or vellus hair, during the first few months of life due to dropping maternal hormone levels. The replacement hair that grows in during infancy often has a completely different color, density, and texture. Blonde toddlers frequently transition into dark brunette children as eumelanin production naturally increases with age.

Because genetic calculators deal exclusively in percentages, they cannot illustrate what a child's facial features and hair will look like together. OurBaby lets parents explore these inherited traits visually. By uploading a single photo of each parent, you can generate an imagined portrait of your future child at selectable ages from newborn to school age in realistic studio and casual settings.

Preview your baby's imagined look

Newborn setting included — one credit per photo.