According to financial planning expert Rakshith H D, the ideal SIP amount cannot be determined solely based on expected returns and investment tenure. The correct approach involves working backwards from financial goals rather than forward from investment capacity. This methodology ensures that major life milestones such as house purchases, children's education, marriage, and retirement planning are properly integrated into the investment strategy.
For retirement planning, the expert recommends the need-based method over the income replacement method, as it is more practical and realistic. Assuming a current age of 30 years, monthly expenses of ₹50,000, retirement age of 60, and life expectancy of 85 years, the monthly expenses at retirement would rise to approximately ₹2.88 lakh at an assumed inflation rate of 6%. To maintain the same lifestyle for 25 years post-retirement, with 6% return on investments and 4% inflation, the real rate of return works out to approximately 1.92%.
Based on these assumptions, the required corpus for retirement planning would be approximately ₹6.84 crore. To accumulate this corpus over 30 years with a 12% return, the recommended SIP amount would be approximately ₹19,500 per month. The expert suggests considering annual SIP increases to account for income growth, which can significantly improve the final corpus. For other goals like house purchases or education, inflation-based calculations can be used to estimate future costs and determine appropriate SIP amounts.
The popular 15-15-15 SIP rule suggests investing ₹15,000 monthly for 15 years at a 15% annual return to reach ₹1 crore. While compounding is powerful, achieving this target faces significant real-world challenges. India's Nifty 50 TRI has averaged around 11.8% to 14.2% over long periods, with realistic long-term annual growth expectations for diversified equity funds typically between 11% and 14%. The Reserve Bank of India's repo rate remains steady at 5.25%, indicating stable economic conditions rather than exceptionally high investment growth.
According to expert analysis, while equity mutual funds have historically delivered returns of 12-14%, it is advisable to assume a conservative 12% return for planning purposes to create a margin of safety. The appeal of the 15-15-15 rule lies in its simplicity and clear goal, with compounding showing that over ₹74 lakh of the final ₹1 crore could come from returns rather than principal. However, investors must consider inflation's impact, with India's consumer price inflation predicted to reach 4.5% to 5.5% by fiscal year 2026-27. Additional costs include 0.5% to 2.5% annual expense ratios for actively managed funds, capital gains taxes on long-term gains over ₹1.25 lakh annually at 12.5% tax rate, and short-term gains taxed at 15%.
