Pasig is 2.7 times larger than Mandaluyong.
Area: 11 km2 calculated
Mandaluyong, officially the City of Mandaluyong, is one of the cities and municipalities that comprise Metro Manila in the Philippines. Wikipedia
Area: 31 km2 calculated
Pasig, officially the City of Pasig is one of the highly urbanized cities of Metro Manila in the Philippines and was the former capital of the province of Rizal prior to the formation the National Capital Region. Wikipedia