Blood Type Inheritance Calculator
Look up which child blood types are possible for any ABO parent combination with probabilities.
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Child blood types that may appear
Child blood types that will not appear
All parent combinations reference
| Parents | Possible child types | Impossible child types |
|---|---|---|
| A + A | A、O | B、AB |
| A + B | A、B、AB、O | — |
| A + AB | A、B、AB | O |
| A + O | A、O | B、AB |
| B + B | B、O | A、AB |
| B + AB | A、B、AB | O |
| B + O | B、O | A、AB |
| AB + AB | A、B、AB | O |
| AB + O | A、B | AB、O |
| O + O | O | A、B、AB |
Blood Type Inheritance Calculator
Find out which blood types your child could have based on ABO blood type inheritance. Select the mother's and father's blood type above to instantly see the possible and impossible child blood types with their probabilities.
The ABO blood system determines blood type through two inherited alleles (A, B, or O). Each parent contributes one allele, and the combination determines the child's phenotype. For example, a parent with type A blood may carry the genotype AA or AO.
All Parent Combinations
The table below lists all 10 unique parent blood type pairs and their inheritance outcomes. Since blood type inheritance is symmetric, A+B is the same as B+A.
How It Works
Each parent passes one of their two alleles to the child. The allele pairs combine to form the child's genotype, which determines their blood type phenotype:
- A — genotype AA or AO
- B — genotype BB or BO
- AB — genotype AB
- O — genotype OO