Las Vegas is 11% larger than Mobile, Alabama.
Area: 363 km2 calculated
Las Vegas, officially the City of Las Vegas and often known as simply Vegas, is the most populous city in the state of Nevada and the county seat of Clark County. Wikipedia
Area: 329 km2 calculated
Mobile is the county seat of Mobile County, Alabama. The population within the city limits was 195,111 as of the 2010 United States Census, making it the third most populous city in the U.S. Wikipedia