Using the criteria of the Big Mac Index developed by The Economist in 1986 as a way to measure if currencies are valued at the right level, the International Business Times created this visualization showing how many minutes a minimum-wage worker needs to work in order to buy a Big Mac burger.
As it turns out, a minimum-wage worker in Afghanistan needs to work 372 minutes (6.2 hours) in order to buy a Big Mac burger. In contrast, a minimum-wage worker in Australia needs to work only 18 minutes to buy a Big Mac burger.
The average weekly income in the US has been going up in the last fifty years, at least in nominal terms, as seen in the first graph. The price of a gallon of gas has been trending up as well, with spikes beginning in 2002 up to 2008, when gas prices decreased dramatically as a consequence of the economic recession. In 2010 gas prices increased again and continue rising to this day, as seen in the second graph. It is worth noting that the number of gallons of gas that can be purchased by a person earning an average income has been decreasing steadily since 1998.