Predict possible blood types of a child based on parents' blood types using genetics.
Predict possible blood types from parents.
The Blood Type Prediction Calculator uses genetic principles to determine which blood types are possible when two people have children. Blood type is inherited through genes—specifically the ABO gene system and the Rh factor—following Mendelian genetics patterns that can be reliably predicted once both parents' blood types are known.
Understanding blood type genetics has practical applications beyond curiosity. It's important for pregnancy planning (Rh incompatibility can cause complications), blood transfusions, and can even help in paternity cases. Each person carries two ABO alleles (inherited from each parent) and the blood type expressed depends on which alleles dominate. Type O is recessive, meaning both alleles must be O to express type O blood, while A and B are codominant—if you have both, you're type AB.
The Rh factor (positive or negative) follows similar rules. Rh+ is dominant over Rh-, so a person with one positive allele will be Rh+. Two Rh- parents can only have Rh- children, but two Rh+ parents can potentially have Rh- children if both carry the recessive allele. This calculator focuses on ABO type predictions; Rh factor follows separately.
A and B are codominant; O is recessive to both A and B.
| Parent 1 | Parent 2 | Possible Child Types |
|---|---|---|
| A | A | A, O |
| A | B | A, B, AB, O |
| A | O | A, O |
| B | B | B, O |
| B | O | B, O |
| AB | AB | A, B, AB |
| AB | O | A, B |
| O | O | O only |
Parents: Type A × Type B. Both could be AO or BO. Possible outcomes: Type A (AO or AB from A parent), Type B (BO or AB from B parent), Type AB (A from one, B from other), Type O (O from each parent).
Related tools: Due Date Calculator for pregnancy planning, Ovulation Calculator for conception timing, and Pregnancy Weight Gain Calculator for healthy pregnancy.
Blood type follows Mendelian genetics. Each parent passes one ABO allele (A, B, or O). A and B are codominant, O is recessive. Two O parents = only O children. A×B = A, B, AB, or O possible.
No. Two O parents can only have O children since O is recessive. If a child is A or B, one parent must carry the A or B allele, even if they appear as type O.
At least one parent must have A allele and one must have B allele. AB×anyone (except OO) can produce AB. Two O parents cannot have AB child—genetics makes it impossible.