SIP Calculator

How to use this calculator

Start with your monthly SIP amount, the annual return you want to assume, and how long you'll stay invested. Two optional fields change the picture meaningfully:

• Annual step-up: raises the SIP by a fixed percentage every year, the way most fund houses' step-up/top-up facilities work. Matching it to your expected salary growth (commonly 5–10%) keeps your investing rate constant as a share of income.
• Initial lump sum: money invested on day one alongside the SIP, useful when you're deploying a bonus and starting a SIP at the same time.

The chart stacks what you invested against what compounding added, and the table tracks both year by year. The fourth metric always shows the step-up counterfactual (with a 10% step-up if you left it at zero, without one if you set it), so the comparison is one glance away.

How SIPs actually work

A SIP, short for systematic investment plan, is a standing instruction to buy mutual fund units for a fixed amount on a fixed date each month. The amount is constant; the number of units varies with that day's NAV. When the market falls your ₹10,000 buys more units, when it rises it buys fewer, so your average purchase cost per unit sits below the average NAV over the period. That's rupee-cost averaging, and it's worth stating plainly: it is not a return-enhancing trick. A rising market means your early cheap units were the best buys you'll get, and a lump sum invested at the start would have caught them all. The real benefit of a SIP is discipline: it automates investing before spending can happen, removes the "is now a good time?" decision entirely, and keeps you buying through downturns, which is precisely when most investors stop.

The default projection shows the shape of the outcome: ₹10,000 a month for 15 years at an assumed 12% grows to about ₹49.96 lakh, of which ₹18 lakh is your money and ₹31.96 lakh is growth, a 2.78× multiple on what you put in. Stretch the same SIP to 20 years and it reaches roughly ₹98.93 lakh: the last five years contribute nearly as much as the first fifteen, which is the compounding argument for starting early and not interrupting.

Step-up SIPs are the practical upgrade most plans miss. A SIP that stays at ₹10,000 for 15 years shrinks year after year relative to a growing salary. Adding a 10% annual step-up to the default plan lifts the maturity value from ₹49.96 lakh to about ₹85.98 lakh, a ₹36 lakh improvement, of which ₹20.13 lakh is extra money you invested and the rest is growth on it. You invest more in total (₹38.13 lakh vs ₹18 lakh), but the increases arrive gradually, in step with income.

One distinction worth knowing before you compare this projection with a fund factsheet: this calculator assumes a constant return every year, while real SIP returns are reported as XIRR, the internal rate of return across your actual dated purchases, which can differ noticeably from the fund's headline point-to-point return. Both are legitimate numbers; they're just answers to different questions.

Formula and methodology

A level SIP with end-of-month installments is a future-value annuity:

With an annual step-up of s, each year's installments are (1 + s) times the previous year's, so the calculator simulates month by month rather than using a single closed form. The same engine produces the year-by-year table. An initial lump sum adds a P(1 + i)ⁿ term on top.

For the defaults: i = 0.12 ⁄ 12 = 0.01 and n = 180, giving (1.01)¹⁸⁰ = 5.9958 and FV = 10,000 × (5.9958 − 1) ⁄ 0.01 ≈ ₹49,95,802, matching the headline result to the rupee.

Worked example

What changes the result

• Duration beats everything. The flat default SIP reaches ₹23 lakh in 10 years, ₹49.96 lakh in 15, ₹98.93 lakh in 20. Each extra five years roughly doubles the outcome at 12%, so stopping early is the most expensive choice available.
• The return assumption is a range, not a fact. At 10% instead of 12%, the default lands at ₹41.45 lakh; at 14%, ₹60.58 lakh. Plan against the lower bound, treat the upper as upside.
• Step-up percentage. Linking it to real salary growth keeps the plan sustainable; setting 10% when raises run 5% eventually forces a downgrade, which breaks the discipline that makes SIPs work.
• Expense ratios come straight out of returns — a fund charging 1.5% more than another needs to outperform by that much every year just to tie.

Assumptions and limitations

• Real equity-fund returns are volatile, not a smooth 12% — actual SIP outcomes depend on the sequence of good and bad years, and reported fund returns use XIRR over actual dates. This projection is a planning centerline.
• Results are pre-tax. Indian mutual fund taxation (LTCG/STCG rates, holding-period rules) has changed several times; check the current rules before assuming a net figure.
• Installments are modeled on time every month; skipped or paused months reduce the outcome below the projection.
• No exit loads, expense ratios, or advisory fees are modeled — net them out of the return you enter.