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Blood type frequency

How Rare Is My Blood Type?

Choose your blood type to see its estimated frequency in the United States, how it compares with the eight main ABO/Rh types, and what that means for blood donation.

By BloodTypeCalc.com Editorial TeamPublished Suggest a correction

Rare does not mean unhealthy

How common a blood type is has nothing to do with a person's health. Frequency simply reflects how often a combination of ABO and RhD antigens appears in a population. A less common type is not a medical problem; it mainly affects how easily a matching donor can be found if a transfusion is ever needed.

Why blood-type frequencies vary

Blood-type frequencies differ between countries and ancestral populations, and different organizations measure them using different donor pools and methods. That is why one source may list a slightly different percentage than another. The figures here are general U.S. educational estimates and are not a live census.

Why common blood types are still needed

Common types such as O positive and A positive are in constant demand precisely because so many patients have them. O negative is valued for emergency use before a patient's type is known. Every type matters: blood services rely on a steady supply of both common and less common types.

See who each type can help on the blood donation compatibility calculator.

AB negative versus other rare blood types

Within the eight main ABO/Rh types, AB negative is the least common in this dataset. That is different from the blood types doctors call clinically “rare,” which involve unusual antigens outside the ABO and RhD systems—for example the Bombay phenotype or rare antigen-negative profiles. This tool only compares the eight main types, so it cannot identify the rarest blood types in the world.

Frequently asked questions

What is the least common main blood type in the United States?
In this dataset, AB negative is the least common of the eight main ABO/Rh types, at roughly 0.6% of the U.S. population—about 1 in 167 people. Frequencies vary by population and source.
Is O negative the rarest blood type?
No. O negative is estimated at about 6.6% of the U.S. population, which makes it less common than the positive types but not the rarest of the eight main types. AB negative is the least common in this dataset.
Is a rare blood type unhealthy?
No. Blood type frequency describes how common a type is in a population. It does not indicate health, fitness, or disease. A less common type simply means fewer matching donors are available.
Are these worldwide statistics?
No. These are general educational estimates for the United States. Blood type frequencies differ substantially between countries and ancestral populations, so worldwide figures would look different.
How is the “1 in N” figure calculated?
It is calculated as 100 divided by the estimated percentage, rounded to the nearest whole person. For example, 0.6% becomes 100 / 0.6 ≈ 167, shown as about 1 in 167 people.

Keep exploring

Blood donation compatibility calculatorCompare a donor and recipient for red cells or plasma.Blood type compatibility chartThe full 8x8 donor and recipient matrix.All eight blood types explainedAntigens, antibodies, and inheritance for each type.
About these figures: percentages are general U.S. educational estimates from the Stanford Blood Center, which credits the AABB Technical Manual, 18th Edition. They are not a live census and vary by population and source.

Sources

Information on this page is paraphrased from the following authoritative sources.

  1. Blood Types (general U.S. frequency estimates, crediting the AABB Technical Manual, 18th Edition)(opens in a new tab)Stanford Blood Center
  2. Facts About Blood and Blood Types(opens in a new tab)American Red Cross