In the United States, AB-negative is the rarest blood type, while O-positive is the most common. Your blood type is based on genetics and whether it contains certain antigens. While AB/Rh-negative ...

Here's a detailed look at the eight main blood types, from the least to the most common, and a special mention of the rarest blood type in the world. Prevalence: 37.4% of the population O-positive ...

But which is the rarest? Here's what to know. Based on statistics, the rarest blood type is AB negative. According to the American Red Cross, AB negative blood type occurs in "1% of Caucasian ...