Business people shelter from the rain under outside a luxury store in Tokyo, Japan, February 15, 2016. Tokyo makes the list.
The index measures the combined cost of residential and office rental per person per year across leading world cities to give an idea of how much it takes to maintain an employee in any given city.
While it's aimed at employers - giving them an idea of labour costs - the fact that it includes property prices means it gives everyone a good idea of the relative cost of living in various cities.
Yolande Barnes, head of Savills world research, says in an emailed statement: "World cities can become a victim of their own success when rents rise to the point where affordability becomes an issue.
"Rapid urbanisation demands supply elasticity - the test for the top Alpha cities is to supply new business quarters and residential neighbourhoods while capturing the characteristics that made the city attractive in the first place. Growth without social, economic, or environmental loss is perhaps one of the biggest challenges facing our world cities today."
The average total cost of office and housing accommodation per worker, per year in the 20 cities measured is $56,855 (£40,654). Savills looked at a combination of established world cities and up-and-coming rivals, dubbed "upstarts" by Savills.
Check out the ranking of the most expensive cities below.