12 fast-food chains taking over America

One of the best ways to see what chains are truly thriving in the $255 billion fast-food industry isn't measured by the number of locations, but instead, how much money each location makes.

One chain was able to rake in an average of nearly $4 million a year at each restaurant, allowing it to overtake chains twice its size when it comes to system-wide sales.

Meanwhile, in 2015, Baskin-Robbins made an average of just $233,000 per location and each Subway location made an average of $424,300 in sales.

QSR Magazine recently released its analysis of the 50 biggest brands in the quick-service industry.

Here are the top 12, ranked in order of average sales per unit in 2015.