FREE TOOLS
What blood type a child can inherit
The ABO and Rh possibilities for a child, from both parents’ blood types. Mendelian genetics, worked out properly.
How this is worked out
ABO type is decided by two alleles, one from each parent. A and B are co-dominant and O is recessive, so a parent who is type A carries either AA or AO — and which one they carry changes what they can pass on. This tool treats both possibilities as equally likely and averages across them.
Which means these are possibilities, not predictions. If the grandparents' types are known the real odds narrow sharply, and the Rh figures are the roughest here, since a Rh-positive parent may or may not carry a negative allele. A blood type is confirmed by a test, never by arithmetic — and this tool is a genetics explainer, not a paternity test.
