Blood Type Compatibility Chart

This chart shows which blood types can safely give and receive red blood cells. A transfusion is safe only when the recipient has no antibodies against the donor's antigens.

O− is the universal donor (can give red cells to every type). AB+ is the universal recipient (can receive red cells from every type).

Red Blood Cell Donor Chart

Find the recipient's type in the left column. A green cell means that donor type is safe.

Recipient ↓ / Donor → O−O+A−A+B−B+AB−AB+
AB+✓✓✓✓✓✓✓✓
AB−✓✕✓✕✓✕✓✕
A+✓✓✓✓✕✕✕✕
A−✓✕✓✕✕✕✕✕
B+✓✓✕✕✓✓✕✕
B−✓✕✕✕✓✕✕✕
O+✓✓✕✕✕✕✕✕
O−✓✕✕✕✕✕✕✕

Quick Donor & Recipient Summary

Blood TypeCan Donate Red Cells ToCan Receive Red Cells From
O−Everyone (universal donor)O−
O+O+, A+, B+, AB+O−, O+
A−A−, A+, AB−, AB+O−, A−
A+A+, AB+O−, O+, A−, A+
B−B−, B+, AB−, AB+O−, B−
B+B+, AB+O−, O+, B−, B+
AB−AB−, AB+O−, A−, B−, AB−
AB+AB+Everyone (universal recipient)

Why Compatibility Matters

Red blood cells carry A, B, and Rh (D) antigens on their surface. Blood plasma carries antibodies against the antigens a person does not have. If a recipient receives red cells carrying an antigen their plasma has antibodies for, those antibodies attack the donor cells, causing agglutination (clumping) and a potentially fatal transfusion reaction.

That is why O− blood, which carries no A, B, or Rh antigens, is safe for anyone, and why AB+ recipients, who carry no anti-A, anti-B, or anti-Rh antibodies, can receive from anyone.

Practice with the Blood Typing Game

Note: This chart covers red blood cell (packed RBC) compatibility, which is what most transfusions and the Blood Typing Game use. Plasma compatibility runs in the opposite direction (AB is the universal plasma donor). Always follow clinical guidance for real transfusions.