The wedding ring is generally worn on the ring finger of the left hand in the former British Empire, certain parts of Western Europe and Central and Eastern Europe. These include: Ireland, the UK, France, Italy, Portugal, Sweden, Finland, Czech Republic, Slovakia, Switzerland, Croatia, Slovenia, and Romania.
The wedding ring is worn on the ring finger of the right hand in some Orthodox and a small number of Catholic European countries and some Protestant Western European countries. These include: Bulgaria, Greece, Georgia, Latvia, Lithuania, Macedonia, Russia, Serbia, Ukraine, Austria, Belgium, Denmark, Germany, Hungary, Poland, Netherlands [if not Catholic], Norway and Spain.
In other words, there is no clear reason/rule which hand a country uses.
World maps
some people also have it on both hands 
(and some on neither)
(and some on neither)
Italy's north south genetic divide revealed: First-ever study into Italians' genetic diversity reveals it dates back 19,000 years and evolved differently because of contrasting environmental and ecological circumstances
This was likely to happen to the Italians as they kept roman all over the place.
Poland was always about 70% support for DP.
Isle of Man ENDS social distancing rules to 'get society back to normal' after no new deaths on the island for 22 days
Isle of Man? Is that pc, should it now be called Isle of Fluid Gender?
Google maps after protestors in Bristol tore down a statue of slave trade Edward Coulston and threw it in the river
Yet they take months to change country names
