Blood Type Inheritance

Which blood types can a child have? Pick both parents' ABO blood types.

Parent 1

Parent 2

ABO inheritance chart

Parental blood type	The blood type of the child	Blood types that do not appear in children

About ABO blood type inheritance

Human blood types come in a variety of forms, each determined by genetic factors and possessing immunological properties. The most prevalent and commonly recognized blood type system is the ABO blood group system, which is classified into four types: A, B, AB, and O.

Each parent passes one of their two ABO alleles (A, B or O) to the child. A and B are co-dominant and O is recessive, so a parent with blood type A may carry the genotype AA or AO. This table provides a quick reference for determining the possible blood types of offspring.

Rare variants (such as the Bombay phenotype or cis-AB) can produce exceptions. This tool is for general information only and is not a paternity or medical test.