If you're learning Spanish or preparing for a geography quiz, the question "¿Cuántos países hay en América Central?" has a straightforward answer: siete (seven).
From north to south, they are:
To answer naturally: "Hay siete países en América Central: Belice, Guatemala, Honduras, El Salvador, Nicaragua, Costa Rica y Panamá."
Note: Sometimes Mexico is mistakenly included, but geographically and culturally, Central America begins at Mexico's southern border. The Caribbean islands (Cuba, Dominican Republic, etc.) are also separate from the Central American mainland.