Blood type chart for parents and children
Which blood types a child can inherit from each pair of parents, from the simple ABO grid to all 36 ABO + Rh combinations.
ABO inheritance chart
| Parent ↓ / Parent → | O | A | B | AB |
|---|---|---|---|---|
| O | O | O, A | O, B | A, B |
| A | O, A | O, A | O, A, B, AB | A, B, AB |
| B | O, B | O, A, B, AB | O, B | A, B, AB |
| AB | A, B | A, B, AB | A, B, AB | A, B, AB |
Rh factor inheritance
| Parents | Child can be | Chance of Rh− |
|---|---|---|
| Rh+ × Rh+ | Rh+ or Rh− | 0% to 25% |
| Rh+ × Rh− | Rh+ or Rh− | 0% to 50% |
| Rh− × Rh− | Rh− only | 100% |
How to read it
Find one parent’s ABO group on the left and the other across the top. The cell lists every ABO group the child could have. Combine with the Rh table for the full blood type.
The chart shows what is possible, not how likely it is. For odds, which depend on hidden alleles, use the blood type calculator or step through the Punnett square.
Not a paternity test. A child whose type seems impossible for the listed parents usually points to a record or lab error, or to rare variants such as cis-AB or the Bombay phenotype. Only DNA testing settles parentage.
Full chart: all 36 parent pairings
Percent ranges cover every genotype the parents could carry. A single number means the odds are fixed. Tap a pairing for its own page with genotype tables and pregnancy notes.
| Parents | O+ | O- | A+ | A- | B+ | B- | AB+ | AB- |
|---|---|---|---|---|---|---|---|---|
| O+ × O+ | 75% – 100% | 0% – 25% | — | — | — | — | — | — |
| O+ × O- | 50% – 100% | 0% – 50% | — | — | — | — | — | — |
| O+ × A+ | 0% – 50% | 0% – 12.5% | 37.5% – 100% | 0% – 25% | — | — | — | — |
| O+ × A- | 0% – 50% | 0% – 25% | 25% – 100% | 0% – 50% | — | — | — | — |
| O+ × B+ | 0% – 50% | 0% – 12.5% | — | — | 37.5% – 100% | 0% – 25% | — | — |
| O+ × B- | 0% – 50% | 0% – 25% | — | — | 25% – 100% | 0% – 50% | — | — |
| O+ × AB+ | — | — | 37.5% – 50% | 0% – 12.5% | 37.5% – 50% | 0% – 12.5% | — | — |
| O+ × AB- | — | — | 25% – 50% | 0% – 25% | 25% – 50% | 0% – 25% | — | — |
| O- × O- | — | 100% | — | — | — | — | — | — |
| O- × A+ | 0% – 50% | 0% – 25% | 25% – 100% | 0% – 50% | — | — | — | — |
| O- × A- | — | 0% – 50% | — | 50% – 100% | — | — | — | — |
| O- × B+ | 0% – 50% | 0% – 25% | — | — | 25% – 100% | 0% – 50% | — | — |
| O- × B- | — | 0% – 50% | — | — | — | 50% – 100% | — | — |
| O- × AB+ | — | — | 25% – 50% | 0% – 25% | 25% – 50% | 0% – 25% | — | — |
| O- × AB- | — | — | — | 50% | — | 50% | — | — |
| A+ × A+ | 0% – 25% | 0% – 6.3% | 56.3% – 100% | 0% – 25% | — | — | — | — |
| A+ × A- | 0% – 25% | 0% – 12.5% | 37.5% – 100% | 0% – 50% | — | — | — | — |
| A+ × B+ | 0% – 25% | 0% – 6.3% | 0% – 50% | 0% – 12.5% | 0% – 50% | 0% – 12.5% | 18.8% – 100% | 0% – 25% |
| A+ × B- | 0% – 25% | 0% – 12.5% | 0% – 50% | 0% – 25% | 0% – 50% | 0% – 25% | 12.5% – 100% | 0% – 50% |
| A+ × AB+ | — | — | 37.5% – 50% | 0% – 12.5% | 0% – 25% | 0% – 6.3% | 18.8% – 50% | 0% – 12.5% |
| A+ × AB- | — | — | 25% – 50% | 0% – 25% | 0% – 25% | 0% – 12.5% | 12.5% – 50% | 0% – 25% |
| A- × A- | — | 0% – 25% | — | 75% – 100% | — | — | — | — |
| A- × B+ | 0% – 25% | 0% – 12.5% | 0% – 50% | 0% – 25% | 0% – 50% | 0% – 25% | 12.5% – 100% | 0% – 50% |
| A- × B- | — | 0% – 25% | — | 0% – 50% | — | 0% – 50% | — | 25% – 100% |
| A- × AB+ | — | — | 25% – 50% | 0% – 25% | 0% – 25% | 0% – 12.5% | 12.5% – 50% | 0% – 25% |
| A- × AB- | — | — | — | 50% | — | 0% – 25% | — | 25% – 50% |
| B+ × B+ | 0% – 25% | 0% – 6.3% | — | — | 56.3% – 100% | 0% – 25% | — | — |
| B+ × B- | 0% – 25% | 0% – 12.5% | — | — | 37.5% – 100% | 0% – 50% | — | — |
| B+ × AB+ | — | — | 0% – 25% | 0% – 6.3% | 37.5% – 50% | 0% – 12.5% | 18.8% – 50% | 0% – 12.5% |
| B+ × AB- | — | — | 0% – 25% | 0% – 12.5% | 25% – 50% | 0% – 25% | 12.5% – 50% | 0% – 25% |
| B- × B- | — | 0% – 25% | — | — | — | 75% – 100% | — | — |
| B- × AB+ | — | — | 0% – 25% | 0% – 12.5% | 25% – 50% | 0% – 25% | 12.5% – 50% | 0% – 25% |
| B- × AB- | — | — | — | 0% – 25% | — | 50% | — | 25% – 50% |
| AB+ × AB+ | — | — | 18.8% – 25% | 0% – 6.3% | 18.8% – 25% | 0% – 6.3% | 37.5% – 50% | 0% – 12.5% |
| AB+ × AB- | — | — | 12.5% – 25% | 0% – 12.5% | 12.5% – 25% | 0% – 12.5% | 25% – 50% | 0% – 25% |
| AB- × AB- | — | — | — | 25% | — | 25% | — | 50% |
Frequently asked questions
Can a child have a different blood type from both parents?
Yes. An A parent and a B parent can have an O child if both carry O, and an AB child is different from either. Two Rh-positive parents can have an Rh-negative child.
Which parent combinations can never produce type O?
Any pairing where one parent is AB (with standard alleles), because the AB parent always passes on A or B.
What blood type can I be based on my parents?
Find your parents’ pairing in the full chart below (or enter them in the blood type calculator). Every type with a percentage is possible for you; a dash means it is not expected under normal inheritance. Only a blood test tells you which one you actually are.
Can I be O positive if my parents are not?
Yes, as long as each parent carries an O gene, which A and B people often do (genotypes AO and BO), and at least one parent carries the Rh-positive D gene. An AB parent cannot normally pass on O.
Which combinations always give the same type?
O × O always gives O, and Rh− × Rh− always gives Rh−. So two O negative parents have O negative children.