Mutual Fund Calculator

If you have a fixed amount to invest, should you put it in as a lumpsum today, or spread it monthly as a SIP? This calculator takes the same total budget and runs both paths side by side, showing you exactly how much the timing difference is worth over your investment horizon.

What is a Mutual Fund Calculator?

A mutual fund calculator projects the future value of an investment made either as a single lumpsum or as a systematic investment plan (SIP). This version compares both strategies using the same total rupee amount, so you can see the actual gap that comes purely from timing, since lumpsum money compounds from day one while SIP contributions trickle in over time.

Your Investment Budget

Same total budget, two strategies: invest it all today vs spread it monthly. See which compounds harder.

Total Amount to Invest (₹)

The total you'll deploy either as one lumpsum today or spread as monthly SIPs.

Investment Duration (Years)

For SIP, this is also the number of months you'll spread the budget over (years × 12).

Expected Annual Return (% p.a.)

Equity MFs typically 10–14%; debt MFs 6–8%; index funds 11–13% historically.

Inflation Rate (%)

India's long-term CPI is around 5–7%. Used for real return rate metrics.

Monthly SIP Equivalent

₹0

Total ÷ (Years × 12)

The Verdict

—

Lumpsum Path

Invest the full amount today, hold for the duration.

₹0

—×

SIP Path

Spread monthly over the duration.

₹0

—×

Side-by-Side Breakdown

Metric	Lumpsum	SIP	Difference

Growth Trajectories

Both curves end at their respective Future Values. The gap shows compounding's head start — lumpsum money has been growing since day 1.

Key Insights

Year-by-Year Comparison

Year	Lumpsum Value	SIP Value	Difference	LP Multiple	SIP Multiple

Advanced Metrics

Beneath the headline numbers — these reveal what's really happening.

Real Return Rate

Nominal return after inflation (same for both)

Effective Monthly Rate

For SIP: (1 + r)^1/12 − 1

Doubling Time (Lumpsum)

— yrs

At this rate, principal doubles every

A breakdown of Lumpsum vs SIP and the trade-offs each strategy implies.

1. The Same Total Budget, Two Timing Strategies

You decide a total amount to invest — say ₹12 lakh over 10 years. The choice: deploy it all in one shot today (Lumpsum), or spread it evenly month by month (SIP). Both strategies put the same total rupees in, but the timing differs profoundly. Lumpsum money is exposed to compounding from day 1; SIP money trickles in over time, so each rupee gets less time to grow.

2. The Two Formulas

Lumpsum: FV = P × (1+r)ⁿ. Annual compounding on the entire principal for the full duration.

SIP: FV = SIP × [((1+r_m)¹²ⁿ − 1) / r_m] × (1+r_m) where r_m = (1+r)^1/12 − 1. This is the annuity-due formula with the effective monthly rate. We use the effective rate (not the simple r/12) because it correctly accounts for compounding — this matches what platforms like Groww and Coin display.

3. Why Lumpsum Wins on Paper

At a constant, positive rate of return, Lumpsum will always beat SIP for the same total investment. Why? Because all your money has been growing since month 1. With a SIP, your final installment in month 120 has had zero time to compound — it just sits there at face value.

4. So Why Do Real Investors Choose SIPs?

Three reasons SIPs dominate in practice, despite losing this theoretical comparison:

(a) Rupee-cost averaging. Real markets aren't constant-rate — they go up and down. SIPs buy more units when prices are low, fewer when high, which can produce better returns than a single mistimed lumpsum during volatile periods.

(b) Behavioural discipline. SIPs automate investing. They remove the timing question (“is this a good time to invest?”) and force consistency.

(c) Capital availability. Most people don't have ₹12L sitting in a bank account. SIPs let you invest from monthly income.

This calculator assumes a constant rate (best-case for Lumpsum). In a real market with volatility, the gap typically shrinks significantly — and SIPs sometimes win.

5. Tax & Real Value

Both paths apply a flat 12.5% LTCG rate on gains. The Real Value column shows the future amount in today's purchasing power (FV ÷ (1+inflation)ⁿ).

Caveats & Disclaimer

Returns are illustrative. Mutual fund investments are subject to market risk; past performance does not guarantee future results. The constant-rate model is a simplification — in reality, returns vary year to year. The 12.5% LTCG assumption applies to equity/equity-oriented holdings held longer than 1 year. SIP tax in reality is calculated per installment based on holding period. Consult a financial advisor for personalised guidance.

One Fund's Comparison Isn't Your Family's Full Picture

This tool compares one investment decision. Most families hold mutual funds across multiple AMCs and platforms bought at different times, some as lumpsum, some as SIP, and rarely reviewed together as a single portfolio. Knowing the theoretical SIP versus lumpsum answer matters less than knowing what your family’s actual combined mutual fund position looks like right now.

How WealthNest.AI Helps Beyond This Calculator

WealthNest.AI aggregates every mutual fund your family holds, across every AMC and platform, into a single dashboard through the RBI-regulated Account Aggregator framework, so you always know your real combined position, not just a projection.

WealthNest.ai - AI-powered personalized family office for your wealth | Product Hunt

See this alongside every other account your family holds, all in one place. Download the WealthNest.AI app to get started.

Frequently Asked Questions

Does lumpsum always beat SIP?

At a constant, positive return rate, yes, lumpsum wins on paper because it compounds from day one. Real markets aren't constant though, so SIPs benefit from rupee-cost averaging during volatile periods.

Why do most investors still choose SIPs?

Behavioural discipline and capital availability. Most people don't have a large lumpsum sitting idle, and SIPs remove the pressure of deciding whether now is a good time to invest.

How is tax calculated on the comparison?

Both paths apply a flat 12.5% LTCG rate on gains, matching India's long-term capital gains tax on equity and equity-oriented mutual funds.

What return rate should I use for comparison?

Equity mutual funds have historically delivered 10 to 14% CAGR long term, debt funds 6 to 8%, though actual returns vary by fund and market cycle.

Can I see my actual SIP and lumpsum returns, not just projections?

Yes. WealthNest.AI tracks your real mutual fund holdings and their actual performance across every fund house you've invested through.