This question can come up anywhere in the interview, but it more commonly comes towards the end. This not only gauges your expectations, but your self-awareness of how the interview has gone. Ultimately, this is where you show your hand and communicate how you equate your self worth. When calculating your self worth, you want to use more than your current salary as a baseline. You don't yet know how frequently they offer performance reviews and pay raises, so your projected pay for the next five years is of value, as well as any other benefit that lowers your cost of living. This should include any bonuses or incentives, commuter perks, employee resources such as mental health care, health/dental/vision, retirement packages, stock options, PTO, etcetera. Once you find where they're meeting, exceeding, or wanting in this regard, you can adjust your number accordingly. Be open, realistic, and honest.