Oakland, California is 28% larger than Hayward, California.
Area: 117 km2 calculated
Hayward is a city located in Alameda County, California in the East Bay subregion of the San Francisco Bay Area. With a population in 2014 of 149,392 Hayward is the sixth largest city in the Bay Area and the third largest in Alameda County. Wikipedia
Area: 150 km2 calculated
Oakland is a major West Coast port city in the U.S. state of California. The Port of Oakland is the busiest port for San Francisco Bay and all of Northern California. Wikipedia