Portland, Oregon is 4.9 times larger than Ann Arbor, Michigan.
Area: 77 km2 calculated
Population: 116,121 (2012)
Ann Arbor is a city in the US state of Michigan and the county seat of Washtenaw County. The 2010 census recorded its population to be 113,934, making it the sixth largest city in Michigan. Wikipedia
Area: 376 km2 calculated
Population: 603,106 (2012)
Portland is the largest city by population in the U.S. state of Oregon, near the confluence of the Willamette and Columbia rivers. Wikipedia