The way to say "how are you" in Spanish depends on the level of formality and whether you are addressing one person or multiple people.

• Informal, singular (e.g., a friend): ¿Cómo estás?
• Formal, singular (e.g., a stranger, elder, or professional setting): ¿Cómo está usted?
• Informal or formal, plural (talking to a group): ¿Cómo están?
• Another casual way to say "how are you?" is: ¿Qué tal? which means "How's it going?" or "How are things?"

These are the most common and widely used expressions to ask "how are you" in Spanish.