I've been trying to figure this out for a while?

Question:My dad's side of the family are from Trinidad and Tobago/Barbados and the other Caribbean Islands
Now on my mom's side...
But my great grandma is a quarter mexican, a quarter Navajo, and the rest African-american[her mom married a black man]
my great grandfather was half american indian[blackfoot] and half African-American
what would that make me? I'm sure it barely comes down to me

Best Answer - Chosen by Asker: My dad's side of the family are from Trinidad and Tobago/Barbados and the other Caribbean Islands
Now on my mom's side...
But my great grandma is a quarter mexican, a quarter Navajo, and the rest African-american[her mom married a black man]
my great grandfather was half american indian[blackfoot] and half African-American
what would that make me? I'm sure it barely comes down to me

Your question is in the genealogy area, which is quite correct.
If one makes the attempt to find accurate "percentages", there are two things you need... first, you need both sides (ie dad's and mom's). For example, you might figure your mother to be a certain part Blackfoot... but if your father also had that in his background, it would affect your equation(s). The other thing needed, IF you were intent on the answer, would be quality documentation of each individual.
Just for analogy, ok?.. the simple thing would be to say that YOU are 1/8th of EACH of your gr grandparents, and for the sake of that analogy, say that each of them were from a different heritage but "full" English, German, Navajo, etc. For some.. it is just that easy, but for many Americans, we already descend from various ancestors who are NOT "full" anything. On mom's side, you mention great grandmother/ grandfather. But you only have part of mom's ancestry there, so the 'other' ancestors would be needed too.
IF you had solid documentation of (example) the Navajo line, if gr grandma is 1/4 that, her children are 1/8th; her grandchildren 1/16th; her gr grandchildren 1/32nd. I repeat.. all of this is dependent upon 'proof', since many lines and families pass down oral history that is more tradition than fact.
Math wise- someone is full English, and the other is 1/2 French, 1/2 German.. you'll need the old fashioned lowest common denominator. The English person is actually 2/2.
So.. if you only have part of the information, you won't accurately be able to figure YOU. You may figure mom out (with the other persons included), where you would only be 1/2 of whatever fraction she is.
Nothing wrong with saying that you have Navajo, AfricanAmerican, Trinidadian (if that is the right word) in your heritage, without the attempt to figure the exact numbers.
One thing that we do get a lot of here, are persons who ONLY want to know their Native percentage, so they can apply for tribal enrollment, and thus (they think) qualify for financial benefits. That certainly does not apply to all persons who are researching their heritage, so the comment was uncalled for.

lucky, think of all the scholarships you qualify for. you may not have to pay a dime for college.

That makes you very lucky to have such a rich and varied ancestry,