The amount you need in retirement is roughly proportional to how much you spend while working, so that if you save 15% of your gross salary throughout your care

The amount you need in retirement is roughly proportional to how much you spend while working, so that if you save 15% of your gross salary throughout your career and invest it in stock, you should be able to retire by 65 and maintain a similar lifestyle in retirement to what you lived while working. The salary is not what matters, it is the savings rate.