The below BIA created Blood Quantum calculation chart is used by the BIA to calculate a person’s degree of Indian blood, issuance of a BIA certified CDIB (Certificate of Degree of Indian Blood). Also, may be used by various Indian Tribal governments for enrollment into that Tribe.
'The BIA sets no minimum blood quantum requirement for acknowledgment purposes, but does require descent from a historic tribe. If your group decides to establish a blood quantum requirement for membership, that is your own decision. However, it is not required by the acknowledgment regulations."
What is blood quantum?
Blood quantum is the amount of Indian blood you possess as determined by the number of generations of Native people you descend from, and it's the process that the federal government uses to say whether they consider you a Native American or not. Between 1885-1940 census rolls, the 1900 special Indian census, the Dawes Rolls, Durrant Rolls, and land conveyances involving Native people were taken. Based on that information, if any of your ancestors were on those rolls, you may be able to receive a Certificate of Indian Blood (see below). For example, if your great-grandmother was 100% Indian and your great-grandfather was non-Indian, their child (your grandmother or grandfather) would be ½ Indian blood. If your 1/2 Indian grandparent married a non-Indian, your mother or father would be 1/4 Indian blood. If your mother or father married a non-Indian, then you would be 1/8. Of course, the percentages change if there were marriages between Native people and your blood quantum or Indian blood would be more. As you can see from the above explanation, the bottom number gets larger as your blood quantum decreases; therefore it is essential that if you are applying for any services, you figure the blood quantum correctly.
How do I get a Certificate of Indian Blood (CIB)?
A CIB can often be obtained from the Bureau of Indian Affairs (BIA) regional or area...