A worked example
Investing ₹10,000/month for 15 years at an assumed 12% annual return produces a projected maturity value of roughly ₹50,45,760 — of which only ₹18,00,000 was actually invested; the rest, over ₹32 lakh, is projected growth from compounding. Extending the same SIP to 20 years instead of 15 nearly doubles the maturity value to around ₹99,91,480, despite "only" 5 more years of contributions.