What's your blood type?
Complete Blood Type Compatibility Chart
Rows = Donor, Columns = Recipient. ✓ = compatible for red blood cell donation.
| Donor ↓ / Recipient → | O- | O+ | A- | A+ | B- | B+ | AB- | AB+ |
|---|
Based on ABO and Rh blood group system compatibility for red blood cell transfusion.
Understanding Blood Type Compatibility
What Are Blood Types?
Your blood type is determined by the presence or absence of certain antigens on the surface of your red blood cells. The two most important systems are the ABO system (types A, B, AB, and O) and the Rh factor (positive or negative). Together, these create the 8 common blood types: A+, A-, B+, B-, AB+, AB-, O+, and O-.
Why Does Compatibility Matter?
When receiving a blood transfusion, your immune system will attack red blood cells that have antigens your own blood lacks. For example, if you have type A blood, your body sees type B antigens as foreign and will destroy those cells. This is why matching blood types correctly is critical for safe transfusions.
O- blood has no A, B, or Rh antigens, meaning it can be safely given to anyone in an emergency. O- donors are always in high demand at blood banks.
AB+ blood has A, B, and Rh antigens, so the immune system recognizes all blood types as "self." AB+ individuals can receive red blood cells from any donor.
Blood Type Distribution
The most common blood types vary by ethnicity and region, but globally:
- O+ — Most common (~37% of population)
- A+ — Second most common (~33%)
- B+ — Third (~12%)
- AB+ — Fourth (~4%)
- O- — Universal donor (~7%)
- A- — (~6%)
- B- — (~2%)
- AB- — Rarest (~1%)
Plasma Donation Has Different Rules
This tool shows red blood cell compatibility. For plasma donation, the rules are reversed: AB type plasma (no antibodies) is the universal plasma donor, while O type plasma can only go to O recipients. Always consult medical professionals for actual transfusion decisions.