Blood Type Compatibility ChartUpdated June 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

O-

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 +

AB+

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. Prophylaxis has reduced the rate of Rh sensitisation from around 13-16% in the pre-prophylaxis era to under 1% today.

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

Frequently Asked Questions

Who can O-negative blood donate to?

O-negative red cells can be given to all 8 blood types: O-, O+, A-, A+, B-, B+, AB-, and AB+. This is why O-negative is called the universal red cell donor. It carries no A, B, or Rh-D antigens, so it triggers no antibody response in any recipient.

What blood type is the universal donor?

O-negative is the universal red cell donor because it can be transfused into any of the 8 blood types. Only about 6.6% of US donors are O-negative (American Red Cross), so it is in constant short supply and is the type hospitals reach for in emergencies when a patient's blood type is unknown.

What blood type is the universal recipient?

AB-positive is the universal red cell recipient. AB+ people carry A, B, and Rh-D antigens, so their immune system makes no antibodies against A, B, or Rh, and they can receive red cells from all 8 blood types. For plasma the rule is inverted: AB is the universal plasma donor.

Can O-negative receive blood from any type?

No. O-negative is the universal donor but the most restricted recipient: an O-negative patient can only receive O-negative red cells. This is why O-negative patients on transfusion or transplant waiting lists have a narrower pool of compatible donors.

What is the most common blood type?

O-positive is the most common blood type, at about 37.4% of US donors and roughly 38% globally (American Red Cross, Stanford Blood Center). A-positive is the next most common at about 35.7% of US donors.

What is the rarest blood type?

Among the 8 main types, AB-negative is the rarest at about 0.6% of US donors. B-negative (about 1.5%) is the next rarest. Far rarer still are types outside the ABO/Rh system, such as the Rh-null phenotype and the Bombay phenotype.