How long does it take?
A very common, slightly more impersonal way to ask. It's like saying 'How long does one take?'
A common synonym for 'tarda', used widely in South America. It can sound slightly more formal.
Another direct equivalent, literally 'How much time does it take?'. Very common in Mexico and Central America.
Excuse me, how long does the bus take to get to the center?
To make the cake, how long does it take in the oven?
I'm going to Bogota next week. How long does the flight take from here?
The process is fast. It doesn't take much time.
The verbs 'tardar', 'demorar', and 'tomar' are all used to ask 'how long it takes'. While all are understood everywhere, which one is most common varies by country.
'¿Cuánto tiempo tarda?' and '¿Cuánto tiempo toma?' are the most frequent. 'Demorar' is understood but less common in everyday speech.
'¿Cuánto se demora?' is extremely common here. You will hear it constantly in contexts like asking a taxi driver or waiting for service.
'¿Cuánto tarda?' and '¿Cuánto demora?' are both very common. 'Demorar' is used frequently in formal and informal situations.
'¿Cuánto se tarda?' and '¿Cuánto tarda?' are standard. They do not use 'demorar' or 'tomar' in this context as frequently as in Latin America.
Saying '¿Cuán largo?' — This is a direct translation of 'How long?', but 'largo' in Spanish refers to physical length (like a long table), not duration of time. For time, always use 'cuánto tiempo'.
Using 'tener' (to have). — Asking '¿Cuánto tiempo tiene?' means 'How much time do you have?'. It doesn't ask how long an activity takes. The correct structure requires a verb like 'tardar', 'demorar', or 'toma'.
Only saying '¿Cuánto tiempo?' — While people might understand you from context, '¿Cuánto tiempo?' ('How much time?') is an incomplete question. You need to add a verb: ¿Cuánto tiempo tarda/demora/toma?