Blood Type Compatibility Checker
Check blood type compatibility for transfusion and donation. Select your blood type to see who you can donate to and receive from. Based on ABO and Rh factor compatibility rules. Free and private.
Select Your Blood Type
Full Compatibility Chart
| Blood Type | Can Donate To | Can Receive From |
|---|---|---|
| O− | All types | O− |
| O+ | O+, A+, B+, AB+ | O+, O− |
| A− | A−, A+, AB−, AB+ | A−, O− |
| A+ | A+, AB+ | A+, A−, O+, O− |
| B− | B−, B+, AB−, AB+ | B−, O− |
| B+ | B+, AB+ | B+, B−, O+, O− |
| AB− | AB−, AB+ | A−, B−, AB−, O− |
| AB+ | AB+ | All types |
How Blood Type Compatibility Works
Blood type compatibility depends on two systems: ABO (A, B, AB, O) and Rh factor (positive or negative). When receiving a transfusion, the donor's blood must be compatible with the recipient's — incompatible blood can cause a serious immune reaction. The ABO system determines which antigens are on your red blood cells, while the Rh factor indicates the presence of the D antigen.
Key Blood Type Facts
Universal Donor: O− can donate red blood cells to anyone
Universal Recipient: AB+ can receive red blood cells from anyone
Most Common: O+ is the most common blood type globally (~37%)
Rarest: AB− is the rarest blood type (~1%)
ABO Blood Group System
Your ABO blood type is determined by antigens on your red blood cells. Type A has A antigens, Type B has B antigens, Type AB has both, and Type O has neither. Your plasma contains antibodies against the antigens you lack — this is why mismatched transfusions are dangerous. Your body attacks foreign antigens.
Why Blood Type Compatibility Matters
Receiving incompatible blood triggers an immune response where antibodies attack foreign red blood cells, causing them to clump (agglutination). This can lead to kidney failure, shock, and even death. That's why blood banks carefully cross-match blood before every transfusion. Knowing your blood type is essential for emergency preparedness.
Blood Type and Pregnancy
Rh compatibility is important during pregnancy. If an Rh-negative mother carries an Rh-positive baby, her body may produce antibodies against the baby's blood cells (Rh incompatibility). This is managed with RhoGAM injections. ABO incompatibility between mother and baby is usually less severe but can cause mild jaundice in newborns.