SIP calculator — monthly investing, with year-by-year growth

A ₹10,000 monthly SIP at 12% becomes roughly ₹1 crore in 20 years, of which only ₹24 lakh is your money. Seeing that split change over time is what makes the maths feel real.

Time matters more than amount. Investing ₹10,000 for 30 years instead of 20 nearly triples the final value while only increasing your contribution by half.

A step-up SIP that rises 10% a year roughly doubles the final corpus compared with a flat SIP over the same period, because each increase compounds for the remaining years.

Calculators are the tools people return to — a loan decision this month, a tax check at year end, a BMI reading at a clinic visit. Reaching for a page that uploads nothing and logs nothing makes the return visit a comfortable one.

Every calculation runs in your browser as you type. There is no request in flight, so there is no privacy-policy asterisk to read: the salary, the loan amount, the medical figures and the dates you enter are never transmitted.

Results are shown with the working rather than as a bare number. That matters when a loan officer, a school form or a tax portal wants the figure to be justifiable, and it matters more when the figure is one you are going to argue with.

The sip calculator on this page is deliberately narrow: it answers one question, states the assumptions beside the answer, and does not ask for an email or an account first. That is the whole design — a calculator you can open, use and close without leaving anything of yourself behind.

Payments around these numbers have their own conventions. Indian EMIs are almost always charged on the reducing balance, which is why interest dominates the early years; fixed deposits compound at whatever frequency the bank’s terms say, typically quarterly, and the effective annual yield is what should be compared across instruments. Nothing here is financial advice — it is arithmetic on the figures you supply, with the convention stated so you can check it.

The figure that matters is often not the one you asked for. On a loan, the monthly instalment is fixed by your cash flow while the total interest is what changes with the tenure; on a tax computation, the useful output is the difference between two regimes rather than one regime’s liability; on a retirement projection, the assumption that does the most damage is a return figure that is one percentage point too optimistic over thirty years.

Accepted inputs are PDF files up to 50 MB. SVG, HTML and other script-bearing formats are refused outright rather than sanitised, because a file that can execute code has no business being re-encoded — and an upload field that accepts one is a security hole rather than a feature. The tool works on one file at a time, which keeps the result unambiguous.

Each instalment is compounded for its own remaining period using monthly compounding at the annual rate divided by twelve. Contributions are treated as arriving at the start of each month. The schedule is built year by year, and the step-up model increments the instalment at every twelve-month boundary before continuing. Returns are assumed to be level, which is a modelling choice, not a forecast. The arithmetic follows the published formulas rather than approximations: loan instalments use the standard reducing-balance annuity formula; recurring and fixed deposits compound at the frequency the instrument specifies; tax and slab figures are applied in the order the statute defines, including surcharge and cess where relevant; age is computed on the calendar by borrowing months the way an eligibility clause does, not by dividing total days. All of it is evaluated in your browser with double-precision floating point, and each result is rounded only for display, which is why the figure you see and the figure you recompute agree to the rupee. The calculation runs locally in your browser. The page or its code may still require a connection to load, and offline use is not guaranteed. Review the assumptions and independently verify important decisions.