San Francisco is one-fifth the size of Toronto, which grew to an area of about 240 square miles as a result of the city's "amalgamation" in 1998 — at which time the city's downtown core, now commonly referred to as "Old Toronto," joined with the neighboring municipalities of York, East York, Etobicoke and Scarborough to form a megacity.
A comparison of regional geography reveals the expanse of the Greater Toronto Area — which measures about 2.5 times the area of the San Francisco Bay Area. However, the Bay Area is about 20 percent more dense when it comes to population and jobs (see graphs in our article Dual Identity.)
San Francisco and the Greater Toronto Area
How big is the city?: City land vs. regional land area
Source: San Francisco Planning Department, http://www.sfgov.org/site/planning_index.asp; City of Toronto City Planning, http://www.toronto.ca/torontoplan/index.htm