Gilbert, Arizona is 51% larger than Surprise, Arizona.
Area: 363 km2 calculated
Gilbert is a town in Maricopa County, Arizona, United States, located southeast of Phoenix, within the Phoenix metropolitan area. Once known as the "Hay Shipping Capital of the World", Gilbert is currently the most populous incorporated town in the United States. Wikipedia
Area: 239 km2 calculated
Surprise is a city in Maricopa County, Arizona, USA. The population was 30,848 at the 2000 census; however, rapid growth has boosted the city's population to 117,517 at the 2010 census, an increase of 281%. Wikipedia