Mutual Fund Calculator
Investing a monthly SIP and a one-time lump sum at the same time? This free mutual fund calculator combines both, and shows your total invested, estimated gains, and maturity value — plus exactly what a fund expense ratio quietly takes from it.
Your investment plan
Advanced options
Optional: add a yearly contribution, step the SIP up each year, fine-tune the term with extra months, or model the sales charges some share classes carry. Everything recalculates from the same projection when you press Calculate.
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Your projection
- The projection is two calculations added together: the future value of the monthly SIP series plus the future value of the lump sum, each compounded over the same horizon.
- Worked example from the guide: a $500 monthly SIP plus a $10,000 lump sum at 10% for 10 years → $129,213.43 on $70,000 invested — $59,213.43 of estimated gains.
- An expense ratio is charged on the whole balance every year: in the guide’s example a 1% fee quietly consumes $18,687.64 — 24.55% of the final value.
Watch your money grow
Each bar is one year: the green part is money you put in, the gold part is the growth on top.
Keep exploring
Three companion tools for planning investments.
How it works
Three steps from a plan to a projected number.
Enter both investments
Type your monthly SIP and any one-time lump sum. Either one can be zero — the calculator handles SIP-only and lump-sum-only plans too.
Set return and horizon
Choose an expected annual return, add your fund’s expense ratio, and pick how many years you plan to stay invested. Everything recalculates live as you type.
Read the breakdown
See total invested, estimated gains, and maturity value — plus a year-by-year chart showing when compounding takes over.
The math behind your projection
A mutual fund projection like this is really two calculations added together: the future value of a monthly SIP series, and the future value of a single lump sum. The SIP uses monthly compounding, so the annual return is divided by 12.
Where M is the monthly SIP, i = r ÷ 12 is the monthly rate, n = the period in months is the number of SIP payments, L is the lump sum, r is the annual return, and y is the number of years. Total invested = (M × n) + L. Estimated gains = maturity value − total invested. With an expense ratio entered, both formulas run on the net return — r minus the expense ratio — and the difference between the two runs is the cost of fees.
The Advanced options extend the same maths instead of replacing it. Extra months simply lengthen n. An annual contribution is a small lump sum added at the start of each year. A step-up raises M by the set percentage at the start of each year. A front-end sales charge comes off every payment before it is invested, and a deferred sales charge (CDSC) comes off the ending value. The Net IRR line then works backwards from the payments you actually made to the single yearly rate that grows them into the maturity value — the return left after every charge you entered.
Worked example — $500/month SIP, $10,000 lump sum, 10% return, 10 years:
| Part | Calculation | Result |
|---|---|---|
| SIP future value | 500 × [((1.008333)¹²⁰ − 1) ÷ 0.008333] × 1.008333 | $103,276.01 |
| Lump-sum future value | 10,000 × 1.10¹⁰ | $25,937.42 |
| Total invested | (500 × 120) + 10,000 | $70,000.00 |
| Estimated gains | 129,213.43 − 70,000 | $59,213.43 |
| Maturity value | 103,276.01 + 25,937.42 | $129,213.43 |
Go deeper
The details that separate a rough guess from a trustworthy projection.
Both benefit from compounding, but on different schedules:
- SIP: each monthly payment compounds for a different length of time — the first payment compounds the longest, the last one barely at all. That is what the annuity formula above captures.
- Lump sum: the entire amount compounds for the full period from day one, so it benefits the most from a long horizon.
- Because of this, a lump sum invested today usually outgrows the same total amount drip-fed as a SIP — assuming the same return. The chart above shows the lump sum’s head start as the taller gold section in the early years.
The calculator assumes one smooth, constant return every year. Real investing does not work that way:
- Volatility: a fund averaging 10% might do +22% one year and −8% the next. The order of those years matters — a crash early hurts less than a crash right before you withdraw.
- Fees and taxes: an expense ratio comes straight out of your return — enter yours above and the headline shows the value after fees. If your fund charges a front-end load or a deferred sales charge (CDSC), you can enter those under Advanced options. Capital-gains tax reduces the number further, and this estimate ignores tax.
- Inflation: 10% nominal growth with 3% inflation is about 7% in real purchasing power.
- Human behavior: pausing the SIP during a downturn is the most common way real returns fall short of projected ones.
Treat the maturity value as a planning illustration, not a promise.
Four optional extras live under Advanced options, all off by default. Each figure below is the calculator’s own default plan — $500 a month plus a $10,000 lump sum at 10% for 10 years — with one option switched on:
- Annual contribution: a second, yearly payment on top of the monthly SIP, made at the start of each year. Adding $1,200 a year puts in $12,000 more and lifts the maturity value from $129,213.43 to $150,250.84.
- Annual step-up: the monthly SIP rises by the set percentage each year — the same simple step-up the SIP Calculator uses. At 10% a year, the $500 SIP pays in $95,624.55 over the decade and the maturity value reaches $178,230.02. For fixed-dollar step-ups and a side-by-side comparison, use the Step-Up SIP Calculator.
- Front-end sales charge: a percentage taken from every payment before it buys units (typical of Class A shares). A 5% charge on the default plan skims $3,500.00 and cuts the maturity value to $122,752.76 — the Net IRR falls from 10.33% to 9.48%.
- Deferred sales charge (CDSC): a percentage of the ending value charged when you sell (typical of Class B and C shares, and usually falling the longer you hold). A 3% CDSC takes $3,876.40 off the default plan at exit, leaving $125,337.03.
The Net IRR line in your results is the return after every charge you enter — expense ratio, sales charges and step-ups included — so it is the honest number to compare share classes with.
Reading the return: what the rate you enter really means
Every projection on this page is driven by one number you type yourself: the expected annual return. Understanding what that number is, and what it is not, matters more than any other input here.
The return you enter is an assumed long-run average used for illustration, not a prediction and not a promise from any fund. Real fund returns vary year to year, sometimes sharply: a fund that averages 7% over thirty years does not return 7% in any single year, and a single bad year early on changes the path even when the average works out the same. That is why the existing guide on this page recommends a long-run average of 8 to 12% for equity-oriented funds for illustration, rather than last year’s hot return. Entering last year’s return, or the best year you can remember, inflates the projection and the disappointment that follows it.
The sensitivity is large, because compounding turns small rate differences into large final differences. Take a single $10,000 lump sum held for 30 years with no further contributions and no fees: at 5% a year it reaches $43,219.42, at 7% it reaches $76,122.55, and at 9% it reaches $132,676.78. The gap between the 5% and 9% outcomes is $89,457.36 on the same $10,000, from two percentage points of assumed return. The same logic applies in reverse to fees: the expense ratio you enter is taken off the return every year, so a 1% fee on a 7% gross return leaves a 6% net return, and over 30 years that 1% quietly consumes nearly a quarter of the final value, as the fee question in the FAQ section shows with this page’s own figures.
| Assumed annual return | $10,000 lump sum after 30 years | Gain over $10,000 |
|---|---|---|
| 5% | $43,219.42 | $33,219.42 |
| 7% | $76,122.55 | $66,122.55 |
| 9% | $132,676.78 | $122,676.78 |
Three habits keep the return assumption honest. First, run the same plan at two or three rates, for example 5%, 7%, and 9%, and treat the range as the answer rather than any single figure. Second, remember that the return is before tax unless you account for tax yourself: this calculator models the charges you enter, including the expense ratio and sales charges, but it does not model your tax bill, so a taxable account keeps less than the projection shows. Third, do not compare funds on the return box alone: two funds with the same assumed return differ by their expense ratio, and the cheaper one keeps more of every year of growth. This calculator is an illustration tool, not investment advice, and it recommends no fund.
XIRR: the return that accounts for timing
A SIP total gain ignores that early instalments compounded longer than late ones. XIRR, the annualised rate equating all dated cash flows, is the right summary for a SIP, computed in a spreadsheet with =XIRR(values, dates). Compare XIRR over the same period, never annualise a short period.
Fees compound against you
A 1 percent expense ratio on $100,000 at 7 percent for 20 years costs about $66,000 against the no-fee figure. The fee never appears as a bill, because it deducts from NAV daily, which is why the calculator shows gross and net figures side by side.
Frequently asked questions
Quick answers about this mutual fund calculator.
How does this mutual fund calculator combine SIP and lump sum?
It calculates the future value of your monthly SIP series and the future value of your one-time lump sum separately, then adds them. You get a combined maturity value plus a full breakdown: SIP contributions, lump-sum invested, total invested, and estimated gains.
What is the SIP future-value formula used here?
SIP future value = M × [((1+i)ⁿ − 1) ÷ i] × (1+i), where M is the monthly amount, i is the monthly rate (annual return ÷ 12), and n is the total number of payments (your period in months). The extra (1+i) factor treats each payment as invested at the start of the month.
What expected annual return should I enter?
Use a long-run average for illustration, not last year’s hot return. Many planners use 8–12% for equity-oriented funds and 5–7% for conservative or debt-oriented ones over long horizons. Try a lower number too — seeing the pessimistic case is the honest way to plan.
Does this calculator account for taxes and fees?
It accounts for every charge you enter: the expense ratio runs through the whole projection, and Advanced options add a front-end sales charge and a deferred sales charge (CDSC) if your share class carries them. It still ignores capital-gains tax, so your real take-home will be a little lower than the after-charge figure.
Can I use it for a lump sum only, or SIP only?
Yes. Set the monthly SIP to 0 for a pure lump-sum projection, or the lump sum to 0 for a pure SIP projection. If you want each style explored on its own page, try the dedicated lump sum calculator or SIP calculator linked above.
How is this different from a step-up SIP calculator?
A step-up SIP increases your monthly payment every year (for example by 10% annually) to model rising income. This calculator now includes the simple version — an Annual step-up (%) field under Advanced options — alongside its lump sum and annual contribution. The dedicated step-up SIP calculator is still the deeper tool, with fixed-dollar step-ups and a side-by-side flat-vs-stepped comparison.
How much can a 1% expense ratio cost me?
Far more than 1% of your money, because the fee is skimmed from your whole balance every year and compounds against you. Example: a $10,000 lump sum growing at 7% for 30 years reaches $76,122.55 with no fee. With a 1% expense ratio the net return drops to 6% and the value falls to $57,434.91 — the “small” 1% fee quietly consumed $18,687.64, or 24.55% of the final value. Enter your own fund’s expense ratio above to see what it costs on your plan.
What return should I enter: last year’s return, or a long-run average?
Enter a long-run average for illustration, not last year’s return and not the best year you can remember. Real returns vary sharply year to year, and a single $10,000 lump sum over 30 years reaches $43,219.42 at 5%, $76,122.55 at 7%, and $132,676.78 at 9%, so the assumption you pick moves the answer more than any other input. Run the same plan at two or three rates and treat the range as the answer, and remember the projection is before tax and is not investment advice.
What return assumption should I use?
A conservative planning assumption, not last year return. Stress-test lower: if the plan works at 6 percent as well as at 10 percent, it is robust; if it only works at 10 percent, it is fragile.
Does a SIP protect against market falls?
No. A SIP averages purchase prices and invests through falls, but if the market falls and stays down, the SIP falls with it. It is a purchase method, not a guarantee.
Why show gross and net figures?
Because the expense ratio deducts from NAV daily and never appears as a bill. Showing both makes the fee visible, and the fee gap is the most reliable predictor of relative fund performance.
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Disclaimer
This calculator provides illustrative estimates for information only — not financial advice. Projections assume a constant annual return with monthly compounding; real mutual fund returns are volatile and can be negative. Results reflect the expense ratio and any sales charges you enter, but ignore taxes and inflation. Past performance does not guarantee future results. Consult a qualified financial adviser before making investment decisions.