Today, I am 30 years old and would like to retire at age 62, 65, 67, etc. I expect I will need $10,000 per month during retirement and hope to live till 85 years old. I have about $50K already saved today. I will likely be aggressive in my early stage of investment (pre-retirement) and seek annual returns of 8%. But as I approach my intended retirement age, I will probably turn more conservative and invest in safer assets at annual returns of 5%. Question: How much will I need to save every month prior to retirement to achieve my goal?