A SIP calculator is a projection tool. It takes three inputs the monthly investment amount, an assumed annual return, and the investment tenure and produces a single output: the estimated corpus at maturity.
The tool does not predict what a fund will return. It applies a fixed rate of return to a stream of monthly investments and shows the compounded result. The assumed rate is the user’s estimate, not a guarantee. Actual mutual fund returns fluctuate, and the calculator’s output is a planning number, not a promise .
The Association of Mutual Funds in India (AMFI) runs the “Mutual Funds Sahi Hai” campaign under SEBI’s guidance to spread awareness about mutual funds as a distinct asset class . SIPs have become a significant channel for retail participation, accounting for nearly 50% of net equity flows in a recent fiscal year .
the formula behind the calculator
The SIP formula is:
M = P × [{(1 + r)^n – 1} / r] × (1 + r)
Where:
- P = monthly investment amount
- r = monthly rate of return (annual rate ÷ 12)
- n = number of monthly instalments
The (1 + r) multiplier at the end accounts for the fact that SIP instalments are typically made at the beginning of each month, not the end .
worked example
A monthly investment of ₹10,000 for 10 years at an assumed 12% annual return.
- P = ₹10,000
- r = 12% ÷ 12 = 0.01
- n = 10 × 12 = 120 months
M = 10,000 × [{(1.01)^120 – 1} / 0.01] × 1.01
M = ₹23,23,390
The total invested amount is ₹12,00,000. The estimated returns are ₹11,23,390 .
what changes the corpus
Three variables drive the output.
The monthly investment amount. Doubling the SIP roughly doubles the corpus, assuming rate and tenure are unchanged.
The assumed return rate. A 2% difference in assumed return compounds significantly over long tenures. On a ₹10,000 monthly SIP over 20 years, the gap between a 10% and 12% assumption runs into lakhs.
The tenure. Time has the largest multiplier effect. Extending a ₹5,000 monthly SIP from 10 years to 15 years at 10% assumed return takes the estimated corpus from roughly ₹10.3 lakh to ₹20.8 lakh, more than double .
using the calculator with real numbers
Bajaj AMC’s SIP calculator provides worked examples across income levels :
A ₹2,500 monthly SIP for 5 years at 10% assumed return builds to approximately ₹1,95,206. Total investment: ₹1,50,000.
A ₹8,000 monthly SIP for 8 years at 12% assumed return builds to approximately ₹12,92,213. Total investment: ₹7,68,000.
A ₹20,000 monthly SIP for 10 years at 13% assumed return builds to approximately ₹49,33,613. Total investment: ₹24,00,000.
These examples show the compounding effect. The longer the tenure, the larger the proportion of returns relative to the invested amount.
what the calculator does not show
The SIP calculator does not account for taxes, expense ratios, or exit loads. Those reduce the actual corpus.
Taxes on equity mutual funds. For equity-oriented funds with over 65% in Indian equities, gains held for more than 12 months are long-term capital gains (LTCG), taxed at 12.5% with the first ₹1.25 lakh of LTCG exempt each year. Gains held for 12 months or less are short-term capital gains (STCG), taxed at a flat 20% . These rates apply regardless of the investor’s income slab .
Expense ratios. Mutual funds charge an annual expense ratio, typically 0.5% to 1.5% for equity funds, deducted from the NAV. A 1% expense ratio reduces the effective return by roughly that amount .
Exit loads. Some funds charge an exit load if units are redeemed within a specified period, often 1% within 12 months.
The calculator’s output is a pre-tax, pre-expense estimate. The actual corpus will be lower.
SIP versus lumpsum
A SIP calculator estimates the value of regular monthly investments. A lumpsum calculator estimates the value of a one-time investment .
The same total amount invested via SIP versus lumpsum can produce different results. A lumpsum invested at the start of a tenure compounds for the full period. SIP instalments enter the market gradually, and each instalment compounds for a different length of time .
SIPs also benefit from rupee cost averaging. Regular purchases happen at different market levels, which smooths the entry price over time. A lumpsum invests everything at a single market level .
frequently asked questions
1. what is a sip calculator?
A SIP calculator is an online tool that estimates the future value of monthly investments in mutual funds based on an assumed rate of return and tenure. It applies the SIP formula to project a maturity corpus, total invested amount, and estimated returns .
2. what is the sip formula?
M = P × [{(1 + r)^n – 1} / r] × (1 + r), where P is the monthly investment, r is the monthly rate of return, and n is the number of instalments .
3. does the sip calculator account for taxes?
No. The calculator shows pre-tax returns. For equity mutual funds, LTCG above ₹1.25 lakh in a year is taxed at 12.5%, and STCG is taxed at 20% . Expense ratios and exit loads also reduce the actual corpus.
4. what return rate should be assumed in a sip calculator?
The return rate is an estimate, not a guarantee. Equity mutual fund returns vary by category and market cycle. A 10-year SIP in some small-cap and mid-cap funds has delivered over 20% annualised, while large-cap and value funds have delivered lower . A conservative assumption for planning purposes is often 10% to 12% for diversified equity funds.
