Lumpsum Calculator

What is a Lumpsum Calculator?

A lumpsum calculator estimates what a single, one-time investment could grow to over a chosen period at an assumed annual rate of return. You enter the amount, the expected return and the number of years; the calculator shows the projected future value, the amount invested and the estimated gain. It is a planning aid for money you already have, such as a bonus, maturity proceeds or an inheritance, rather than money invested in monthly instalments.

Lumpsum Formula

This calculator uses the standard compound-interest formula with annual compounding:

FV = P × (1 + r)n

• FV = future value (projected corpus)
• P = one-time investment (principal)
• r = annual rate of return in decimal form (12% → 0.12)
• n = investment period in years

Estimated returns are FV − P. The year-by-year chart applies the same formula for each year from 0 to n. See the lumpsum methodology page for assumptions and sources.

Worked Example

Suppose ₹5,00,000 is invested for 10 years at a hypothetical 12% a year:

• P = 5,00,000
• r = 12 / 100 = 0.12
• n = 10
• (1.12)¹⁰ ≈ 3.1058
• FV = 5,00,000 × 3.1058 ≈ ₹15,52,924

The estimated gain is ₹10,52,924, roughly twice the original amount, because each year's return is earned on the previous years' returns as well as on the principal. Enter the same inputs above to check the result.

Lumpsum projection at 12% annual return

Future value of different one-time amounts, using the formula above at a constant hypothetical 12% a year:

Illustrative only. Assumes a constant 12% return compounded annually, before costs and taxes. Actual returns vary and can be negative.

Lumpsum vs SIP with the same total investment

Compare ₹12,00,000 invested at once with a SIP of ₹10,000 a month for 10 years (the same ₹12,00,000 in total), both at a constant 12% a year using this site's formulas:

• Lumpsum: about ₹37,27,018
• SIP: about ₹22,40,359

With a constant positive return, the lumpsum always ends higher, because all the money is invested for the full period while SIP instalments are invested gradually. Real markets do not rise in a straight line, and that is where SIPs differ. Spreading purchases buys more units when prices are low and fewer when they are high (rupee-cost averaging). In a toy example with ₹30,000 and unit prices of 100 → 80 → 100, a lumpsum ends at ₹30,000 and three equal instalments end at ₹32,500. If prices instead go 100 → 110 → 121, the lumpsum ends at ₹36,300 and the instalments at ₹33,100. Neither approach is better in every market; a SIP reduces the risk of investing everything at a poorly timed moment, while a lumpsum gets full market exposure from day one.

The Rule of 72

Dividing 72 by the annual return gives a quick estimate of how many years money takes to double. The exact figure is ln(2) ÷ ln(1 + r):

• 6%: rule of 72 gives 12.00 years; exact is 11.90 years
• 8%: rule of 72 gives 9.00 years; exact is 9.01 years
• 12%: rule of 72 gives 6.00 years; exact is 6.12 years
• 15%: rule of 72 gives 4.80 years; exact is 4.96 years

The shortcut is close in the 6 to 10% range and drifts at higher rates, so treat it as a mental check, not a substitute for the calculator.

CAGR Explained

CAGR (compound annual growth rate) is the constant yearly rate that turns a starting value into an ending value over a period: CAGR = (End ÷ Start)^1/n − 1. For example, ₹2,00,000 growing to ₹3,50,000 in 5 years is a CAGR of about 11.84%. The "expected return" you enter above is effectively a CAGR. A simple average of yearly returns can overstate it: a +30% year followed by a −20% year averages 5%, but the CAGR over those two years is only about 1.98%.

STP: a middle path

A systematic transfer plan (STP) is a facility offered by mutual funds in which a lumpsum is first placed in one scheme, typically a liquid or debt fund, and a fixed amount is transferred at regular intervals into another scheme, often an equity fund. It combines a one-time deployment of cash with staggered market entry. The transfers count as redemptions from the source scheme, so each one can have tax and exit-load implications, and the source scheme carries its own risks and returns.

What this calculator does NOT model

• Expense ratio: mutual funds deduct annual costs from the NAV, so the return you receive is lower than the gross portfolio return. Direct plans have lower expense ratios than regular plans of the same scheme.
• Exit load: many schemes charge a fee if units are redeemed within a specified period. Terms differ by scheme and are listed in its scheme information document.
• Taxes (as of October 2026): for listed equity shares and units of equity-oriented funds held for more than 12 months, long-term capital gains above ₹1.25 lakh in a financial year are taxed at 12.5%. Gains on units held for 12 months or less are short-term and taxed at 20%. Other fund categories are taxed differently, and cess/surcharge are extra.
• Volatility and timing: the projection assumes the same return every year. For a single lumpsum held throughout, the order of yearly returns does not change the final value, but the entry point does, and a fall just before you need the money can force an exit at a loss.
• Inflation: results are in nominal rupees. Use the inflation toggle in Results to see the value in today's rupees.

Return rates used on this page are hypothetical and are not a forecast for any fund or index.

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• Step-up SIP Calculator - model a SIP that increases by a fixed percentage each year.
• FD Calculator - estimate maturity on a fixed deposit at a stated interest rate.
• PPF Calculator - project Public Provident Fund maturity over its 15-year term.