Where Does The Last Name Theory Come From? ^{nationality or country of origin}

The surname Theory occurs in Afghanistan more than any other country or territory. It may occur in the variant forms:. For other potential spellings of Theory click here.

How Common Is The Last Name Theory? ^{popularity and diffusion}

The last name Theory is the 4,908,606^th most frequently used surname in the world. It is borne by around 1 in 455,471,620 people. The last name is predominantly found in Asia, where 100 percent of Theory reside; 94 percent reside in South Asia and 94 percent reside in Islamic South Asia. Theory is also the 962,660^th most frequently occurring first name world-wide, borne by 97 people.

This last name is most prevalent in Afghanistan, where it is carried by 13 people, or 1 in 2,473,322. In Afghanistan Theory is mostly found in: Nangarhar, where 31 percent live, Herat, where 23 percent live and Kabul, where 15 percent live. Barring Afghanistan it is found in 2 countries. It is also common in Iran, where 13 percent live and Israel, where 6 percent live.