Many retirement professionals believe it depends on your retirement savings goal. For example, if you manage to accumulate before-tax retirement savings consisting of 5% of your income each year for 30 years, assuming an annual growth rate of 8% per year, you may retire with almost half the income that you were making before retirement. If you save 10% of your income per year, you will be very comfortable in retirement. But if the portfolio’s inflation-adjusted annual return is only 2–3% per year, you would need to save almost 40% of your current annual income just to have half your current income in retirement.