- 1). Find out which generation of your ancestors came to the United States and determine which country each ancestor emigrated from. For example, let's say both of your parents were born in the United States. You have a maternal grandmother who was born in France, a maternal great-grandfather born in England and a maternal great-grandmother born in Sweden. You also have a paternal grandmother born in South Africa, a paternal great-grandmother born in India and a paternal great-grandfather born in China.
- 2). Multiply the number of foreign-born parents you have by 50 to find the percentage of your heritage from the country each of your parents was born in. In the example, neither parent was foreign-born, so this step is unnecessary.
- 3). Multiply the number of foreign-born grandparents you have from each country by 25 to find the percentage of your heritage from those countries. In the example, you have a grandmother from France and a grandmother from South Africa. Multiplying each of these by 25 finds that you're 25 percent French and 25 percent South African.
- 4). Multiply the number of foreign-born great-grandparents you have from each country by 12.5 to find the percentage of your heritage from those countries. In the example, you have a great-grandfather from England and one from China and a great-grandmother from India and one from Sweden. Multiplying each of these by 12.5 finds that you're 12.5 percent English, 12.5 percent Chinese, 12.5 percent Indian and 12.5 percent Swedish.
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