| Blood type of parents | Blood type of children | Ratio |
| A and A | A, O | A:O = 3:1 |
| A and B | AB, A, B, O | AB:A:B:O = 1:1:1:1 |
| A and O | A, O | A:O = 1:1 |
| A and AB | A, AB, B | A:AB:B = 2:1:1 |
| B and B | B, O | B:O = 3:1 |
| B and AB | AB, B, A | AB:B:A = 1:2:1 |
| O and O | O | O = 1 |
| O and AB | A, B | A:B = 1:1 |
| B and O | B, O | B:O = 1:1 |
| AB and AB | A, AB, B | A:AB:B = 1:2:1 |