A lumpsum investment means deploying a single amount into a mutual fund at one point in time, as opposed to spreading it across monthly SIP instalments. Lumpsum works well when markets have corrected significantly, when you have received a windfall (bonus, inheritance, property sale proceeds), or when investing in debt funds where timing risk is lower.

The compounding formula for a lumpsum is: Future Value = P × (1 + r)^n, where P is the principal, r is the annual return rate, and n is the number of years. At 12% annual return, ₹5 lakh invested today grows to approximately ₹15.5 lakh in 10 years and ₹48 lakh in 20 years. The doubling time at 12% is roughly 6 years (Rule of 72: 72 ÷ 12 = 6).

For lumpsum equity investments, avoid deploying the full amount on a single day if market valuations are stretched. Consider a Systematic Transfer Plan (STP) — parking the lumpsum in a liquid or overnight fund and transferring fixed amounts into equity monthly over 6–12 months. This gives the benefit of rupee-cost averaging while keeping the corpus working.

This calculator computes the future value of a one-time investment at a given annual return and time horizon. Use it to project maturity value, compare return scenarios, and determine how much you need to invest today to reach a future corpus target. All calculations assume constant compounding and are for educational purposes only.