What a SIP calculator can and cannot tell you
A systematic investment plan is a standing instruction to invest a fixed amount every month. The maths of its maturity value is an annuity-due: each instalment compounds for however many months remain until maturity, so the first one works for the full term and the last one works for a month. Add those up and you get the figure this calculator returns.
What it tells you is what a constant rate of return would produce. What it cannot tell you is what your fund will actually do, because no fund returns a constant rate. Real sequences arrive as a bad year, two flat years, a strong year — and the order matters much less for a SIP than for a lump sum, but it still means the single number here is a planning benchmark rather than a prediction. Treat it as "what would I end up with if things averaged out", never as a promise.
How to use this calculator
- Enter your monthly instalmentThe amount actually debited each month. If you plan to step it up annually, run the calculator once at your current amount and once at your target to see the range.
- Choose an expected annual returnPick a rate you could defend to someone sceptical, not the best year you remember. Then run it again two or three percentage points lower and check the plan still works.
- Set the duration in yearsThen try the same SIP over five more years. The jump is usually larger than people expect, and it is the most useful thing this calculator shows.
Duration beats amount
Hold ₹10,000 a month and a 12% annual return constant, and vary only the number of years. Every figure below comes from the same formula this page uses.
| Duration | Total invested | Maturity value | Gain as a share of the total |
|---|---|---|---|
| 5 years | ₹6.00 lakh | ₹8.25 lakh | 27% |
| 10 years | ₹12.00 lakh | ₹23.23 lakh | 48% |
| 15 years | ₹18.00 lakh | ₹50.46 lakh | 64% |
| 20 years | ₹24.00 lakh | ₹99.91 lakh | 76% |
| 25 years | ₹30.00 lakh | ₹1.90 crore | 84% |
Doubling the duration from 10 to 20 years doubles what you put in but multiplies the maturity value more than four times. Doubling the monthly amount instead would only double the maturity value. That asymmetry is the entire argument for starting early, and it is arithmetic rather than opinion.
See what your SIPs have actually returned
AIVITTA reads your real holdings and computes the return you actually earned — dated cash flows, benchmark comparison and risk, not an assumed rate.
Why the lump-sum figure is bigger
The comparison on this page invests the same total money as a single amount on day one. It always produces a larger number, because every rupee then compounds for the full term instead of an average of half of it. That is not an argument against SIPs — it is the definition of compounding, and it isolates one thing: the cost of not having the money available at the start.
A SIP is not competing with having a lump sum. It is competing with not investing, and with investing a lump sum badly. Its real advantages are behavioural and practical: it matches how salaried income arrives, it removes the decision of when to enter, and it makes the average purchase price insensitive to any single month. The comparison figure here exists so nobody is surprised later by the arithmetic. If you do have a lump sum to deploy, SIP versus lump sum investing works through the trade-off properly.
Where a SIP calculator misleads
- It assumes a constant return. Real returns arrive unevenly. Two funds with the same average can end at different values if contributions and volatility interact differently.
- It ignores costs and taxes. Expense ratio is already inside a fund's reported NAV return, but exit load, capital gains tax and stamp duty are not in any of these figures.
- It ignores inflation. ₹1.9 crore in twenty-five years is not ₹1.9 crore of today's purchasing power. Subtract your inflation assumption from the return to see the figure in real terms.
- It assumes you keep going. The single largest source of shortfall against a projection is pausing the SIP during a fall — which is exactly when the instalments buy the most units.
- It is not your actual return. For what you really earned, dated cash flows are required. Use the XIRR calculator.
Checking a SIP you already run
This page projects forward from an assumption. To measure backwards from reality, enter each instalment as a dated negative cash flow and your current folio value as a positive one in the XIRR calculator — that gives the annualised return your money actually earned, which is the number worth comparing against the Nifty 50 over the same window. For a single lump-sum investment with no top-ups, the CAGR calculator is the simpler tool.