Blood Type Distribution by Ethnicity and Country
Blood type frequencies vary significantly across ethnic groups and geographic regions. O-positive is the most common type worldwide, but the proportions shift dramatically between populations. Updated June 2026.
Most common blood type by ethnicity
O-positive is the single most common blood type in every major US ethnic group, but its share and the second-most-common type differ markedly:
- Native American: O-positive (about 57%) - the highest O+ share of any group
- Hispanic / Latino: O-positive (about 53%)
- African American: O-positive (about 47%), with B-positive notably common (about 18%)
- Asian / Pacific Islander: O-positive (about 39%), with B-positive the highest of any group (about 25%)
- White / Caucasian: O-positive (about 37%), and the highest Rh-negative rates (about 15% are Rh-negative)
So the headline answer is the same for every group - O-positive - but the biggest ethnic differences show up further down the list. B-positive is roughly three times more common in Asian and African American donors than in White or Hispanic donors, and Rh-negative blood is overwhelmingly a European trait.
Blood type distribution at a glance (US, 2026)
Across the US donor population the approximate ABO/Rh split is O+ 37%, A+ 36%, B+ 8.5%, AB+ 3%, O- 6.6%, A- 6.3%, B- 1.5%, AB- 0.6%. O-positive is the most common type and AB-negative is the rarest.
By race and ethnicity the proportions shift: O-positive ranges from about 37% in White/Caucasian donors to 53% in Hispanic/Latino donors, B-positive is far more common in Asian (about 25%) and African American (about 18%) donors than in White or Hispanic donors (about 9%), and Rh-negative status is predominantly a European trait (about 15% of Europeans versus under 1% in most Asian and African populations).
Why Blood Type Distribution Varies
ABO blood group frequencies in human populations are not uniform - they vary substantially by ethnicity and geographic origin. These differences are the result of evolutionary genetic pressures, population bottlenecks (where a small group founded a larger population, carrying their blood type proportions), and possibly disease resistance advantages.
The B allele, for example, is significantly more common in South Asian and Central Asian populations, making B blood group far more prevalent in India and Pakistan than in Western Europe or the Americas. In Japan, the A allele is particularly common, leading to higher A-type frequencies. Sub-Saharan African populations have very high O frequencies.
Rh-negative status also varies by ethnicity. In European populations, about 15% are Rh-negative. In Asian and African populations, Rh-negative is rare - often under 1%. This means Rh-negative blood types (like O-, A-, B-, AB-) are predominantly a European genetic trait.
US Blood Type Distribution by Ethnicity
| Ethnic group | O+ | O- | A+ | A- | B+ | B- | AB+ | AB- |
|---|---|---|---|---|---|---|---|---|
| White / Caucasian | 37% | 8% | 33% | 7% | 9% | 2% | 3% | 1% |
| African American | 47% | 4% | 24% | 2% | 18% | 1% | 4% | <1% |
| Hispanic / Latino | 53% | 4% | 29% | 2% | 9% | 1% | 2% | <1% |
| Asian / Pacific Islander | 39% | 1% | 28% | 0.5% | 25% | 0.4% | 7% | 0.1% |
| Native American | 57% | 1% | 31% | 3% | 8% | 0.5% | 1% | <1% |
Source: American Red Cross, Stanford Blood Center. Values are approximate percentages based on US blood donor data. Donor populations may not be fully representative of the general population.
Blood Type Distribution by Country
| Country | O+ | A+ | B+ | AB+ | O- | A- | B- | AB- |
|---|---|---|---|---|---|---|---|---|
| United States | 37% | 36% | 8.5% | 3% | 6.6% | 6.3% | 1.5% | 0.6% |
| United Kingdom | 36% | 30% | 8% | 3% | 7% | 8% | 2% | 1% |
| India | 37% | 22% | 32% | 7% | 2% | 0.8% | 1% | 0.2% |
| Japan | 30% | 40% | 20% | 10% | <1% | <1% | <1% | <1% |
| Nigeria | 57% | 20% | 19% | 3% | 1% | <1% | <1% | <1% |
| Brazil | 44% | 33% | 9% | 3% | 6% | 3% | 1% | <1% |
Approximate values based on published population genetics studies and national blood service data. Country-level data is approximate and varies by region within each country.
Why Ethnic Matching Matters for Rare Blood Types
For most transfusions, ABO and Rh compatibility is sufficient. However, patients who require frequent transfusions - especially those with sickle cell disease, thalassaemia, or other haematological conditions - can develop antibodies to minor blood group antigens after multiple transfusions. Once sensitised, subsequent transfusions must avoid not just ABO/Rh mismatches but also mismatches in systems like Duffy, Kell, Kidd, and MNS.
Because minor antigen frequencies vary by ethnicity, patients from a specific ethnic background are more likely to find matched donors from within the same ethnic community. This is why American Red Cross and other blood banks specifically recruit donors from ethnic communities that are underrepresented in the donor pool - not to segregate blood, but to ensure patients from those communities can receive closely matched units.
Sickle cell disease predominantly affects patients of African, Caribbean, Mediterranean, Middle Eastern, and Asian origin. These patients require chronic transfusions and benefit enormously from donors who share their minor blood group antigens. Increasing diversity in the donor pool directly reduces the risk of sensitisation in these patients.
Frequently Asked Questions
What is the blood type distribution in the US?
Across the US donor population the approximate ABO/Rh distribution is O+ 37%, A+ 36%, B+ 8.5%, AB+ 3%, O- 6.6%, A- 6.3%, B- 1.5%, and AB- 0.6%. O-positive is the most common type and AB-negative is the rarest of the eight major types.
What is the most common blood type for each race and ethnicity?
O-positive is the single most common blood type in every major US ethnic group, but its share varies: about 57% in Native American donors, 53% in Hispanic/Latino donors, 47% in African American donors, 39% in Asian/Pacific Islander donors, and 37% in White/Caucasian donors. The bigger ethnic differences appear lower down the list - B-positive is roughly three times more common in Asian (about 25%) and African American (about 18%) donors than in White or Hispanic donors (about 9%), and Rh-negative blood is predominantly a European trait.
How does blood type distribution vary by race and ethnicity?
ABO frequencies shift substantially between groups. Among US donors, O-positive ranges from about 37% in White/Caucasian donors to 53% in Hispanic/Latino donors. B-positive is far more common in Asian/Pacific Islander donors (about 25%) and African American donors (about 18%) than in White or Hispanic donors (about 9%). Rh-negative types are predominantly a European trait.
Which countries have the most B blood type?
The B allele is most common in South and Central Asia. In India around 32% of people are B-positive, compared with roughly 8 to 9% in the United States and United Kingdom.
Are Rh-negative blood types more common in some ethnicities?
Yes. About 15% of people of European ancestry are Rh-negative, while Rh-negative is rare in Asian and African populations, often under 1%. This is why Rh-negative types such as O-, A-, B- and AB- are predominantly a European genetic trait.