The quantity of people with the surname Tarnu that we can find in each country can help us discern the origin of the surname Tarnu, as logic tells us that the place with the most people surnamed Tarnu will be the country or area of origin of the surname Tarnu.
Globalization can make the surname Tarnu be found in almost every country around the globe, but being able to see the density of people residing in a country with the surname Tarnu greatly aids all those who seek a deeper knowledge about the surname Tarnu.