Actually it is all dependent on the immigrant of each of your nationality's. My father is an immigrant, straight from Hong Kong, China (making our family Cantonese, so we speak Cantonese and we make Cantonese food). He is 100% Chinese since my grandma and grandpa were also 100%. My mom's great great grandpa was straight from Germany and was 100% German. My mom's great great grandma and grandpa on the other side were from Czechoslovakia (100% Czechoslovakian).
So, from different nationality breeding (sorry to make it sound inhumane), the nationality loses some of itself. My mom's grandma (Czech) married a man of very mixed nationalities. The percentage loss itself by 50% for the other nationalities to who would be their daughter, my mom's mom (grandma) so my grandma was a bit grandma was 50% Czech and a bunch of other stuff. She married my grandpa on my mom's side whose great grandpa was a man from Germany, who married a woman who all we know was a bit Irish (like 25 percent, but from this calculation makes me hardly Irish). They got married and my mom's great grandpa was also 50% German and 50% other. All his nationality moved down and all we know is that my grandpa on my moms side is around 50% German, but married a woman who was also a bit German to, so we know that my mom is 50% German too. But wait, keep in mind that she is also Czech. That around 40-30% Czech degrades the German, because each generation loses automatically loses 10% of that nationality, she is now 40% German, but the that 40% Czech that carries on to her and makes her all in all, 30% Czech, 40% German and 30% other (from the unknown nationalities from her ancestors).
So, she married my father and since he's an immigrant, making me 1st generation Chinese along with my siblings. All in all, I am am 20% Czech, 10% German and 70% Chinese. But nationality is not just genetics, it is also culture and pride. I lean towards my fathers side because he passed his culture towards me more than my mom did (because she doesn't care about her culture) and the only culture that i have inside my mind and that I was taught was of my father and China and my family. That, giving my a mindset that I am 100% Chinese.
This may just be telling you what i am, but at least try to use this formula to help u calculate yours