How much horsepower does a corolla have?

Depends on model year and any modifications done to the engine. Stock HP for North American bound Corollas range anywhere from a 1st generation Corolla (1966-1969) 1.1L carburated engines with 60HP all the way to a 9th generation 2005-2006 Corolla XRS 1.8L VVTL-i engine with 170HP. Once you get into modified Corollas, the only limit is with how much time, effort, and money will be expended to get your HP goals. Good example is the UK's Fensport Corolla - heavily modified, makes in excess of 650HP.