Child blood type calculator
Explore possible child blood types from the parents' blood groups.
Possible blood types for your child
A+
A-
B+
B-
AB+
AB-
O+
O-
A known blood type does not always identify a genotype. Reliable percentages cannot be calculated from the parents' blood types alone.
Method
Each parent passes on one ABO allele and one RhD variant. The model combines four ABO outcomes and four RhD outcomes, assuming independent Mendelian inheritance.
Formula
P(ABO, RhD) = P(ABO) × P(RhD)Limitations
- A blood type does not always reveal its underlying genotype.
- Rare variants, weak or partial D and exceptional inheritance patterns are not modelled.
- Do not use this tool for parentage, transfusion decisions or pregnancy risk assessment.