Lumpsum Calculator
See how a single lump-sum investment compounds over time. Enter the amount, expected return rate and time horizon to get your projected maturity value.
What is a lumpsum calculator?
A lumpsum calculator estimates the future value of a one-time investment. Unlike a SIP where you invest regularly, a lumpsum means committing a single amount upfront and letting compound interest work over time. This is common for investing a bonus, inheritance, or any windfall.
Enter your investment amount, expected annual return, and time horizon. The calculator shows the projected maturity value and the total returns earned on your initial investment.
How compound interest grows your lumpsum
With a lumpsum, your entire principal starts compounding from day one. Each year, returns are earned on both the original investment and on all previously accumulated returns. This creates exponential growth — the longer the horizon, the more dramatic the effect.
- Principal — the one-time amount you invest upfront.
- Rate of return — expected annual growth rate. Equity markets have historically delivered 10–14% over long periods.
- Time horizon — years you stay invested. The impact of compounding becomes significant only after 7–10 years.
The lumpsum formula
Lumpsum growth uses the standard compound interest formula:
Your estimated returns are FV minus your original principal.
A worked example
Invest 100,000 at 12% per year for 10 years:
| Year | Value |
|---|---|
| Year 1 | 112,000 |
| Year 3 | 140,493 |
| Year 5 | 176,234 |
| Year 10 | 310,585 |
| Returns earned | +210,585 |
Your money more than triples in 10 years at 12%. At 15 years it grows over 5×. The rule of 72 says money doubles roughly every 72 ÷ rate years — at 12%, that's every 6 years.
Lumpsum vs SIP
A lumpsum works best when you have a large amount available now and markets are expected to rise. A SIP averages out your entry price through regular investments and is better suited for monthly salary-based investing. Many investors combine both strategies: SIP for ongoing income, lumpsum for windfalls.