Lumpsum Calculator
₹ Invest once, wait, and let compounding work: future value, wealth gained and your money's ×multiple — with an honesty check on rosy return assumptions.
Anyone with the link can see the numbers included in it.
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Last reviewed: July 20, 2026 · Formulas verified by automated tests before every release.
How do I calculate lumpsum investment returns?
Future value = investment × (1 + annual return)^years. A one-time ₹1,00,000 at an assumed 12% for 10 years becomes about ₹3,10,585 — a ×3.1 multiple, doubling roughly every 6.1 years. The return you type is an assumption: model 10% and 12% both, because markets pay averages over decades, not fixed rates on a schedule.
The formula and the multiple
FV = P × (1 + r)^t · money multiple = FV ÷ P · doubling time ≈ 72 ÷ rate
The ×multiple is the number worth remembering — it's rate and time compressed into one figure. Ten years at 12% is ×3.1; twenty years is ×9.6. That second decade tripling the outcome without a single extra rupee invested is compounding's whole argument — feel it yourself in our 60-second game.
Lumpsum vs SIP vs FD — the honest triangle
Lumpsum maximizes time-in-market and crash exposure alike. SIP trades some expected return for a smoother entry. FD trades growth for a guarantee. The common Indian middle path for a windfall: FD or liquid fund now, systematic transfer (STP) into equity over 6–12 months — discipline without the all-in bet on one entry date.
Sources, assumptions and limitations
- Formula: FV = P(1 + r)^t, annual compounding; doubling check via ln(2)/ln(1+r)
- Assumptions: Constant assumed return for the whole horizon (a modeling simplification — real returns arrive unevenly); pre-tax, pre-fee figures.
- Not included: Capital-gains tax (asset-class and holding-period specific — see FAQ), fund expense ratios, entry/exit loads, inflation adjustment. An assumption above 14% triggers an on-page optimism warning by design.
- Last reviewed: July 26, 2026 by the CalcNotebook team
Frequently asked questions
How is lumpsum return calculated?
Future value = P × (1 + r)^t with annual compounding. ₹1,00,000 invested once at an assumed 12% for 10 years grows to about ₹3,10,585 — the money multiplies ×3.1. The rate is an assumption, not a promise: markets deliver averages, not schedules.
Lumpsum or SIP — which is better?
Neither, universally. A lumpsum puts all money to work immediately — historically ahead in steadily rising markets, but fully exposed to a crash the next month. A SIP spreads entries and smooths the ride at the cost of some upside. The honest hybrid many use: park the sum in an FD or liquid fund and STP it into equity monthly.
Is 12% a realistic assumption?
It sits at the optimistic end of long-run Indian equity index averages, before fees and taxes. Model 10% and 12% side by side and treat anything above 14% as a stress-test of your optimism, not a plan.
What about taxes?
Gains are taxable and the rules differ by asset class and holding period (equity long-term gains above the annual exemption are taxed at rates set in the Finance Act; debt funds follow slab rates). Figures here are pre-tax — verify current rules or ask a tax professional before deciding.