By number of passengers using the airport for the calendar year of 2018.
These are the runway layouts of the 16 most used airports in the world — a brief look at how runways can change with each airport. Unsurprisingly, the USA leads with the largest number of runways, with Dallas/Fort Worth International holding the title with seven in total. Meanwhile, Dubai handles even more passengers a year on just two. Each diagram is to scale and orientated northwards.
Data from Wikipedia. Graphics in part by freepik and Font Awesome.