If you include commuters, London's population is much larger than 12.5%: approximately 14 million people live in the "commuter belt" [1], which would put it at

If you include commuters, London's population is much larger than 12.5%: approximately 14 million people live in the "commuter belt" [1], which would put it at 21% (and a lot more people commute from even further, myself included). Still, London has nothing on Seoul, whose metro area encompasses 49% of South Korea's population. [1] https://en.wikipedia.org/wiki/London_commuter_belt https://en.wikipedia.org/wiki/London_commuter_belt