Lumpsum Investment Calculator
Lumpsum Investment Calculator
What a one-time investment could grow to at an assumed annual return — and what that amount would be worth in today’s money once inflation is taken out. Market returns are not guaranteed.
Lumpsum investment
$1,00,000 invested once for 10 years at 12% a year, with inflation at 6%
Future value of a lump sum
- P
- the amount invested once, at the start
- r
- the expected annual return as a decimal, compounded once a year
- t
- the number of years
- f
- the annual inflation rate as a decimal
Worked example
$1,00,000 invested once for 10 years at 12% a year, with inflation at 6%
(1.12)10 = 3.1058
FV = 1,00,000 × 3.1058 = $3,10,585; gain $2,10,585
(1.06)10 = 1.7908, so in today's money 3,10,585 ÷ 1.7908 = $1,73,429
Real return = 1.12 ÷ 1.06 − 1 = 5.66% a year
1,00,000 invested once, by assumed return and years
| Return | 5 years | 10 years | 15 years | 20 years |
|---|---|---|---|---|
| 6% | $1,33,823 | $1,79,085 | $2,39,656 | $3,20,714 |
| 8% | $1,46,933 | $2,15,892 | $3,17,217 | $4,66,096 |
| 10% | $1,61,051 | $2,59,374 | $4,17,725 | $6,72,750 |
| 12% | $1,76,234 | $3,10,585 | $5,47,357 | $9,64,629 |
| 14% | $1,92,541 | $3,70,722 | $7,13,794 | $13,74,349 |
What a lumpsum projection can and cannot tell you
A lumpsum grows by compounding: each year’s return is earned on the original amount plus every earlier year’s return. The formula assumes the same return every single year. Equity and hybrid funds never do that — they rise and fall — so read the result as what a steady average would produce, not as a forecast. A fund’s past returns do not guarantee its future returns, and a lump sum invested just before a fall takes time to recover, which is one reason some investors spread a large amount over months with a SIP calculator instead.
Inflation is the caveat most projections leave out. At 12% a year for 10 years, $1,00,000 becomes about $3,10,585, but at 6% inflation that buys what $1,73,429 buys today — a real return of about 5.66% a year, not 6%. The real return divides rather than subtracts: (1 + return) ÷ (1 + inflation) − 1. The chart draws both lines year by year: after 5 years the estimate is about $1,76,234, or $1,31,692 in today’s money, and the gap between the blue and the teal line is what inflation takes.
The doubling time shown uses the exact formula. The rule of 72 gives 72 ÷ 12 = 6.0 years against the exact 6.12, close enough for mental arithmetic. Gains on redemption are usually taxable and funds charge an expense ratio that is already taken out of their published returns; exit loads may apply on early redemption. For a deposit with quarterly or monthly compounding use the compound interest calculator; to measure what an investment has actually returned use the CAGR calculator. This is arithmetic on the figures you enter, not financial advice.
Frequently asked questions
How is a lumpsum investment’s future value calculated?
FV = P × (1 + r)t, with r the annual return as a decimal. $1,00,000 at 12% for 10 years is about $3,10,585.
Are the returns guaranteed?
No. Market-linked investments can return more or less than the figure you enter, and can lose money. The calculator shows what an assumed steady return would produce.
What does the value in today’s money mean?
It is the future value divided by the growth in prices over the same years, so you can compare it with what money buys now. At 6% inflation, $3,10,585 in 10 years buys about what $1,73,429 buys today.
Lumpsum or SIP — which gives more?
At the same steady return a lumpsum gives more, because all the money is invested from day one. Real markets are not steady, and a SIP spreads the entry over many prices. The comparison depends on how markets move after you invest, which nobody knows in advance.
Related calculators
References
- U.S. Securities and Exchange Commission, Investor.gov. Compound Interest Calculator. https://www.investor.gov/financial-tools-calculators/calculators/compound-interest-calculator
- Securities and Exchange Board of India (SEBI) / Association of Mutual Funds in India (AMFI). Mandatory risk statement for mutual fund communications: “Mutual fund investments are subject to market risks, read all scheme related documents carefully.”
- Brealey RA, Myers SC, Allen F. Principles of Corporate Finance. McGraw-Hill. Present values, annuities and growing annuities.
- Central-bank inflation targets used as default inflation by currency: Reserve Bank of India (4% CPI, flexible inflation targeting framework); U.S. Federal Reserve (2% PCE); European Central Bank (2%); Bank of England (2% CPI); Bank of Canada (2%); Reserve Bank of Australia (2–3%); Bangko Sentral ng Pilipinas (3% ± 1). Actual inflation often runs above target.