Step-Up SIP Calculator
Raise your monthly investment each year as your income grows, and see both the extra corpus it builds and the extra money it asks for.
Your plan
What it builds
Corpus at the end
from — invested over —
- Wealth gained —
- Instalment in the final year —
- Corpus in today's money —
Against a flat SIP of the same starting amount
- Flat SIP corpus —
- Flat SIP total invested —
- Extra you have to invest —
- Extra corpus you end with —
What this calculator assumes
- The instalment is paid at the start of each month and the step-up applies after every twelfth instalment — the convention every Indian fund house calculator uses.
- The monthly return is the annual figure divided by twelve, again the industry convention, so the number here matches what your AMC's own calculator shows.
- Returns are assumed to be steady and net of the fund's expense ratio. Real equity returns arrive out of order, which changes the outcome even when the average is unchanged.
- Figures are pre-tax and pre-exit-load. No capital gains tax, stamp duty or exit load is deducted.
- Every instalment is paid on time, with no pause, no missed debit and no redemption along the way.
How a step-up SIP is calculated
A step-up SIP — most fund houses call it a top-up SIP — is an ordinary SIP with one extra instruction attached: after every twelfth instalment, raise the amount by a fixed percentage. There is no tidy closed-form formula for it, which is why this calculator walks the plan month by month instead of pretending there is one. Each month it adds that month's instalment to the balance, then grows the whole balance by one month's return. Every twelfth month, the instalment itself steps up.
Two conventions matter and both follow Indian industry practice. The instalment is treated as paid at the start of the month, so it earns a full month's return. And the monthly return is the annual figure divided by twelve — 12% a year becomes 1% a month, not the 0.949% a true effective conversion would give. Matching the convention is deliberate: the number here should agree with your fund house's own calculator rather than quietly differ from it.
Take the default case. You start at ₹10,000 a month, raise it 10% every year, assume 12% a year and run it for fifteen years. The instalment is ₹11,000 in year two, ₹23,579 in year ten and ₹37,975 in the final year. You put in ₹38,12,698 across the fifteen years and finish with about ₹86,83,849. A flat ₹10,000 SIP over the same period puts in ₹18 lakh and finishes at ₹50,45,760. So the step-up costs you ₹20,12,698 more and returns ₹36,38,089 more — roughly ₹181 of corpus for every extra ₹100 committed. That leverage is the honest case for the step-up, and it is also the reason it should not be described as free money.
A step-up keeps your savings rate constant
The strongest argument for a step-up has nothing to do with compounding. It is that a fixed instalment quietly becomes a smaller and smaller share of your income. Someone earning ₹50,000 a month who starts a ₹10,000 SIP is saving 20% of their pay. If the salary grows at 8% a year, it reaches roughly ₹1,46,860 by year fifteen — and that same ₹10,000 is now under 7%. The savings rate has collapsed without a single decision being taken. Every raise in between was absorbed by something.
Setting the step-up close to your realistic annual increment reverses the default. The raise is split before it reaches your account: the savings rate holds, and your standard of living still improves every year, just by less than the full increment. This is the one behavioural mechanism in personal finance that reliably survives contact with real life, because it needs a decision once rather than a decision every April.
Why an early base beats a late catch-up
Compounding is not symmetric across the life of a plan, and this is where most step-up calculators stop short. At 12%, a rupee invested in the first month of a fifteen-year plan becomes ₹6.00 by the end. The same rupee invested with five years left becomes ₹1.82. Early instalments are not slightly more valuable — they are three times more valuable.
Run the comparison with the money held constant. The step-up plan above invests ₹38,12,698 and ends at ₹86,83,849. Suppose instead you invest nothing for five years, then put in exactly the same ₹38,12,698 as ₹31,772 a month across the last ten years. You end with ₹73,81,989 — about ₹13 lakh less for identical money, purely because it arrived later.
The converse deserves the same honesty, because it argues against the step-up. If you could afford to spread that ₹38,12,698 evenly from month one — ₹21,182 a month, flat — you would finish near ₹1.07 crore, roughly ₹20 lakh ahead of the step-up. A step-up is not superior to investing more from the start. It is the best available shape when your income genuinely starts small and grows, and it is a poor excuse for postponing an increase you could make today.
What a 10% step-up actually asks of you
The default 10% looks modest for a year or two and then does something people rarely picture. Run it for twenty years and the final instalment is 6.12 times the first: a ₹10,000 SIP ends at ₹61,159 a month, and the total put in is ₹68,73,000 against ₹24 lakh for the flat version. The plan is only real if your take-home pay compounds at something close to 10% for two decades, after tax, through job changes and the years when the appraisal is a title rather than a rise.
A step-up you abandon in year six is worth less than a smaller one you hold for twenty. Trimming the same fifteen-year plan to a 5% step-up ends the instalment at ₹19,799 rather than ₹37,975 and still builds ₹65,30,752 — well ahead of the flat SIP's ₹50,45,760, and far easier to sustain. Setting the step-up near your realistic increment and raising it in a good year is a better plan than setting an ambitious one and quietly cancelling it.
What this calculator cannot tell you
The return you type is an assumption, not a rate you are entitled to. Equity funds do not deliver 12% a year; they deliver something wildly different each year that may average near 12% over a long stretch. The order matters as much as the average — a poor decade at the end, when the corpus is at its largest and the instalments at their biggest, does far more damage than the same decade at the start. No single-rate calculator, including this one, can show that.
The other things it leaves out are worth listing plainly:
- Tax. The corpus is pre-tax. Equity fund gains are taxed on redemption at whatever rate applies then, and each instalment carries its own holding period.
- Exit loads and stamp duty on purchases, both small but real.
- Your mandate ceiling. The bank debit authorisation you sign has a maximum amount. Register it above the instalment you will reach in the final year, or the SIP fails partway through.
- Whether the fund survives the plan. Fifteen years is long enough for the fund manager to change more than once, and long enough that a scheme merger or a change of mandate can land on you mid-plan.
It also cannot tell you whether market risk is the right risk for the goal. A step-up SIP into an equity fund and a rising contribution to PPF, which pays 7.1% for Q2 FY 2026-27 with a sovereign guarantee, are not variants of the same decision. If the money is needed on a fixed date within five years, the calculator above is answering the wrong question.
Common questions
Is the step-up applied to my original SIP amount or the current one?
To the current one, which is why the instalment compounds rather than rising in equal steps. A 10% step-up on ₹10,000 takes you to ₹11,000 in year two and then to ₹12,100 in year three — not ₹12,000. Over fifteen years that gap is the whole point: the instalment ends at ₹37,975. Some fund houses instead offer a flat rupee top-up — say ₹1,000 more each year — which rises in equal steps and reaches only ₹24,000 by year fifteen, because those fourteen increases never build on each other.
Do I have to register a new SIP every year?
No — every major fund house registers the step-up once, as a top-up instruction attached to the original SIP. The part that catches people is the bank side. The e-mandate or NACH debit you authorise carries a maximum amount fixed at registration, and the bank will reject a debit that exceeds it. If your instalment is going to reach ₹37,975 in year fifteen, the mandate has to be signed for at least that much on day one. Check the mandate limit, not just the SIP amount.
What happens if I cannot afford the step-up in a bad year?
Nothing punitive. A SIP is an instruction you can modify or pause, not a contract with a penalty clause, so you can hold the instalment flat for a year or cut it back. The cost is arithmetic rather than a fee: the base you carry into every later year is lower, and because the missed increase compounds, one skipped step-up in year three costs more than one skipped in year twelve. Set a step-up you can hold through an ordinary bad year rather than a heroic one.
Is a step-up SIP better than simply starting with a larger amount?
No, and it is worth being blunt about it. Spreading the same total money evenly from month one beats the step-up, because the early rupees compound for longer. In the worked example the step-up puts in ₹38,12,698 and ends at ₹86,83,849; the same ₹38,12,698 paid as a flat ₹21,182 a month ends at about ₹1.07 crore. The step-up is the best shape available when your income genuinely starts small — it is not better than having the money early.
Is the corpus shown here before or after tax?
Before. The figure is what the folio is worth, not what reaches your bank account. Equity fund gains are taxed when you redeem, at whatever rate the Finance Act sets at that time, and each SIP instalment is a separate purchase with its own holding period — units bought in the final year are short-term even when the folio is fifteen years old. Redemption is matched first-in, first-out, so a partial withdrawal sells your oldest and most-appreciated units first.
Sources
Rates and rules on this page were read directly from the following sources on the dates shown. Figures change — if you are about to act on one, confirm it at the source.