Blood Type Compatibility ChartUpdated April 2026
Select your blood type below to instantly see who you can donate to and receive from. Switch between transfusion, organ transplant, and pregnancy (Rh factor) modes.
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Covers transfusion, organ transplant, and pregnancy Rh factor
What This Chart Shows
Human blood is classified using the ABO system and the Rh factor. These two systems together give us the 8 common blood types: A+, A-, B+, B-, O+, O-, AB+, and AB-. The letter (A, B, O, or AB) describes which antigens sit on the surface of your red blood cells. The +/- sign describes whether you carry the Rh-D antigen.
Compatibility matters because your immune system produces antibodies against antigens it does not recognise as "self." If you receive blood containing antigens your body does not expect, your antibodies attack the donated red cells, causing a haemolytic transfusion reaction. The same principle applies to organ transplant, though additional matching layers (HLA tissue typing, crossmatch testing) add complexity beyond ABO.
According to the American Red Cross, compatibility rules are fixed by biology and do not change between sources. This chart reflects the same rules published by the Red Cross, Cleveland Clinic, and the American Society of Hematology.
The 8 Blood Types at a Glance
| Type | Can donate to | Can receive from | US % | Global % |
|---|---|---|---|---|
| O+ | O+, A+, B+, AB+ | O+, O- | 37.4% | 38.3% |
| O- | O+, O-, A+, A-, B+, B-, AB+, AB- | O- | 6.6% | 7.2% |
| A+ | A+, AB+ | A+, A-, O+, O- | 35.7% | 27.5% |
| A- | A+, A-, AB+, AB- | A-, O- | 6.3% | 6.1% |
| B+ | B+, AB+ | B+, B-, O+, O- | 8.5% | 22% |
| B- | B+, B-, AB+, AB- | B-, O- | 1.5% | 1.7% |
| AB+ | AB+ | A+, A-, B+, B-, O+, O-, AB+, AB- | 3.4% | 5.1% |
| AB- | AB+, AB- | A-, B-, O-, AB- | 0.6% | 0.9% |
Source: American Red Cross, Stanford Blood Center. Population percentages are approximations based on US donor data and global estimates.
Universal Donor and Universal Recipient Explained
Universal Red Cell Donor
O-negative blood carries no A antigens, no B antigens, and no Rh-D antigen. Because it triggers no antibody response in any recipient, it is compatible with all 8 blood types. Hospitals maintain O-negative reserves for emergencies when a patient's blood type is unknown.
Only about 6.6% of US donors are O-negative, making it perpetually in short supply relative to demand.
Full universal donor guide +Universal Red Cell Recipient
AB-positive people carry both A and B antigens and the Rh-D antigen. Their immune system does not produce antibodies against A, B, or Rh antigens, which means they can accept red cells from any of the 8 blood types.
Note: AB is also the universal plasma donor (plasma rules are inverse - see plasma compatibility).
Full AB+ guide +Transfusion vs. Organ Transplant: Why Both Tabs Exist
The ABO compatibility rules are nearly identical for red-cell transfusion and solid organ transplant. An O-negative donor can theoretically give a kidney to an AB-positive recipient. However, transplant compatibility is not as simple as transfusion compatibility.
Organ transplants require additional tests that blood transfusions do not. HLA tissue typing examines protein markers on white blood cells and organ cells - a closer tissue match means lower risk of rejection over time. A crossmatch test mixes the recipient's serum with the donor's cells to check for pre-existing antibodies (sensitisation). Prior transfusions, pregnancies, or previous transplants can all sensitise a patient against specific donor types.
The kidney-specific complication is the paired exchange program: if a willing living donor is ABO-incompatible with their intended recipient, they can "swap" with another incompatible pair so both recipients receive a compatible kidney. This is coordinated by UNOS and the National Kidney Registry.
For organ transplant guidance, see the UNOS/OPTN website and the National Kidney Foundation.
Full organ transplant compatibility guide +Pregnancy and Rh Factor: When Blood Type Matters
During pregnancy, a small amount of fetal blood can cross the placenta into the mother's circulation - especially during labour and delivery. If the mother is Rh-negative and the fetus is Rh-positive (inherited from the father), the mother's immune system may produce anti-D antibodies against the fetal red cells.
This typically causes no problem in a first pregnancy because sensitisation occurs at delivery. In subsequent pregnancies with an Rh-positive fetus, however, the pre-formed anti-D antibodies can cross the placenta and attack the fetal red cells, causing haemolytic disease of the newborn (HDN).
Anti-D immunoglobulin (trade name RhoGAM in the US) is given to Rh-negative mothers at around 28 weeks of pregnancy and within 72 hours of delivery. According to Cleveland Clinic, prophylaxis has reduced the rate of Rh sensitisation from 10-20% to under 1%.
Use the Pregnancy tab in the tool above to check your specific combination.
Full Rh factor pregnancy guide +Explore More Topics
Universal Donor
Why O-negative is universal
Rare Blood Types
Rhnull, Bombay phenotype, and more
Organ Transplant
Kidney, liver, heart compatibility
Rh Factor Pregnancy
Anti-D and Rh incompatibility
Blood Type Genetics
Punnett squares and inheritance
Plasma Compatibility
Why AB is universal plasma donor
Distribution by Ethnicity
Who has which type worldwide
Find Your Blood Type
5 ways to learn your type
What If No Match?
Autologous donation and alternatives