Lumpsum Investment Calculator

Work out what a single investment made today could be worth after a number of years at an assumed rate of return. Useful for a bonus, an inheritance, maturity proceeds, or any sum you are deciding what to do with.

Free · runs in your browser · updated

Parameters
Total Lumpsum Investment ($)
Expected Annual Return Rate (%)
Investment Duration (Years)
Returns Summary
Invested Principal
$0
Wealth Gain
$0
Future Expected Corpus
$0
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Lumpsum Investment Calculator at a glance

What it does
Calculate what a single one-time investment could grow to over time, with the compound growth formula explained and its assumptions stated plainly.
Where it runs
Entirely in your browser — no data is uploaded
Works offline
Yes, once the page has loaded
Cost
Free, with no account and no usage limit
Category
Financial Calculators

How to use the lumpsum calculator

  1. Enter the amount you are investing today.
  2. Enter an expected annual return, conservatively.
  3. Set the number of years.
  4. Read the projected value and how much of it is growth rather than principal.

The formula

FV = P × (1 + r)ⁿ

P = amount invested today
r = annual rate of return, as a decimal
n = number of years

Worked example. ₹5,00,000 invested at 12% for 15 years: 5,00,000 × 1.1215 = about ₹27.4 lakh. Your principal is ₹5 lakh; the remaining ₹22.4 lakh is compounding.

Note how the growth accelerates. After 5 years the value is about ₹8.8 lakh; after 10 years about ₹15.5 lakh; after 15 about ₹27.4 lakh. The last five years add more than the first ten, which is the whole point of compounding and the reason time in the market matters more than almost anything else.

The rule of 72

Divide 72 by the annual return to get the approximate number of years for money to double. At 12%, that is six years. At 8%, nine years. At 6%, twelve.

It is accurate enough for mental arithmetic between about 4% and 15%, and it is the fastest way to sanity-check a projection. It works in reverse too: if an investment promises to double in three years, that implies a 24% annual return, which should prompt questions about what risk is being taken - or whether the claim is credible at all.

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Lump sum or spread it out?

The honest answer has two parts that point in different directions.

The mathematics favours investing immediately. Markets rise more often than they fall, so money invested sooner is invested for longer. Studies of historical data consistently find that immediate lump-sum investment beats phasing in roughly two thirds of the time.

The behaviour often favours phasing in. The other third of the time matters, because investing a large sum immediately before a sharp fall is precisely the experience that causes people to sell at the bottom and stay out of the market for years. Spreading a lump sum over six to twelve months costs a little expected return and buys a great deal of resilience.

The practical resolution: if the sum is small relative to your existing portfolio, invest it. If it is large enough that a 30% fall would genuinely distress you, phase it in.

What the projection ignores

  • Volatility. A constant rate hides the fact that the value will fall, sometimes substantially, along the way.
  • Taxes. Capital gains tax on redemption reduces what you actually receive.
  • Fees. An expense ratio is deducted annually and compounds against you.
  • Inflation. The projected figure is in today's currency units, not today's purchasing power. ₹27 lakh in fifteen years buys considerably less than ₹27 lakh now.

For a realistic picture, subtract the fee from your assumed return, then run the result through the inflation calculator to see what it is worth in today's money.

This is a calculator, not advice. It applies a standard formula to the figures you enter and assumes a constant rate of return, no taxes and no fees unless stated. Real markets do not behave that way. Nothing here is a recommendation to buy, sell or hold any investment — see our full disclaimer, and speak to a qualified adviser regulated in your jurisdiction before making a financial decision.

Frequently asked questions

Something you would be comfortable defending as conservative. Equity markets have historically returned around 10-12% nominal in India and 7-10% in developed markets over long periods, but no rate is guaranteed and short periods vary enormously.

Statistically, investing immediately beats phasing in about two thirds of the time, because markets rise more often than they fall. Phasing in reduces the risk of the other third, which for a large sum is often worth the cost.

No. The result is in nominal terms. To see what it is worth in today's purchasing power, discount it by your expected inflation rate.

Divide 72 by the annual percentage return to get the approximate doubling time. At 9%, money doubles in about eight years. It is a close approximation for ordinary rates.

Nothing you enter here leaves your browser

Lumpsum Investment Calculator does its work in JavaScript running on your own device. The page loads once, and after that there is no upload step and no server involved — which matters here because your income, loan and savings figures are nobody else’s business.

You can verify this rather than taking our word for it: load the page, disconnect from the internet, and the tool keeps working. Our privacy policy sets out what is and is not collected, and this guide explains why the distinction matters.

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