Portland, Oregon is 6.1 times larger than Gresham, Oregon.
Area: 61 km2 calculated
Gresham is a city located in Multnomah County, Oregon, United States immediately east of Portland. It was named after the American Civil War general, and Postmaster General, Walter Quinton Gresham. The population was 105,594 at the 2010 census, making Gresham the fourth largest city in Oregon. Wikipedia
Area: 376 km2 calculated
Portland is the largest city by population in the U.S. state of Oregon, near the confluence of the Willamette and Columbia rivers. Wikipedia