Blood Types

ABO is the most important of several blood group systems for typing human blood, based on the presence or absence of two antigens (A and B) on the surface of red blood cells. Blood types are A, B, AB, and O.

How Rare Is My Type?*

“The rarest blood type is the type that’s not available when YOU need it!”

Blood Type How Many Have It Frequency
O + 1 person in 3 37.4%
O – 1 person in 15 6.6%
A + 1 person in 3 35.7%
A – 1 person in 16 6.3%
B + 1 person in 12 8.5%
B – 1 person in 67 1.5%
AB + 1 person in 29 3.4%
AB – 1 person in 167 .6%

*These are general estimations for educational purposes only. Actual data may vary. Original source: AABB Technical Manual 18th Edition

Blood Type Compatibility