The Public Profiler site plots eight million last names using data from electoral rolls and phone directories.
The site covers 300 million people in 26 countries, showing the origins of names and where families have moved to.
David Beckham, for example, has an English name, but there are more Beckhams in the US than Britain.
But the region of the world with the highest concentration of people called Beckham was even further from the footballer's east London origins - in the New Zealand province of Northland.
The site - www.publicprofiler.org/worldnames - also reveals which of the five million forenames are most closely associated with different surnames and lists the top regions and cities for each surname. More...