Rarest blood type
AB negative is the rarest of the eight main blood types; O positive is the most common. Here is the full rarity chart.
- 1
0.6% - 2
1.5% - 3
3.4% - 4
6.3% - 5
6.6% - 6
8.5% - 7
35.7% - 8
37.4%
Ranked rarest first. Source: Stanford Blood Center / American Red Cross.
Why AB negative is so rare
AB negative needs three less-common things at once: an A allele from one parent, a B allele from the other, and an Rh-negative allele from both. Multiply those odds together and you land under 1%.
But rare doesn’t always mean in short supply. AB negative patients can receive any Rh-negative red cells (O−, A−, B−, AB−), so they have more options than O negative patients, who can receive only O negative.
The most common blood type
O positive leads at about 37%, with A positive close behind at about 36%. Together they cover nearly three in four Americans.
Rarer than any of the eight
- Rh-null (golden blood): no Rh antigens at all. Around 50 people reported worldwide.
- Bombay phenotype (hh): lacks the H antigen that A and B are built on. About 1 in 10,000 people in India, around 1 in a million in Europe.
- Other rare types lacking high-frequency antigens (for example U-negative, Vel-negative or Duffy-null in some combinations) that need donors from rare donor registries.
Blood type percentages by ancestry (US)
| Type | White | Black | Hispanic | Asian | All US |
|---|---|---|---|---|---|
| O positive | 37% | 47% | 53% | 39% | 37.4% |
| O negative | 8% | 4% | 4% | 1% | 6.6% |
| A positive | 33% | 24% | 29% | 27% | 35.7% |
| A negative | 7% | 2% | 2% | 0.5% | 6.3% |
| B positive | 9% | 18% | 9% | 25% | 8.5% |
| B negative | 2% | 1% | 1% | 0.4% | 1.5% |
| AB positive | 3% | 4% | 2% | 7% | 3.4% |
| AB negative | 1% | 0.3% | 0.2% | 0.1% | 0.6% |
American Red Cross figures, rounded; columns may not total 100%.
Frequently asked questions
What is the rarest blood type?
AB negative is the rarest of the eight standard types, at about 0.6% of the US population. The rarest blood known overall is Rh-null (“golden blood”), with around 50 people reported worldwide.
What is the most common blood type?
O positive, at about 37% of Americans. It is also the most common type globally.
What is the second rarest blood type?
B negative, at about 1.5% of Americans.
Is O negative rare?
Moderately: about 1 in 15 Americans. It is in high demand because it is the universal red cell donor type, which makes it feel scarcer than it is.
Does rarity change by country?
Yes, a lot. Rh-negative blood is uncommon across most of East Asia (well under 1% in China, Japan and Korea) but around 15% in much of Europe. Type B is far more common in South and Central Asia than in Western Europe.