How does an SIP work? What ₹10,000/month actually grows to over 10, 15, and 20 years
An SIP invests a fixed amount monthly in a mutual fund. ₹10,000/month at 12% grows to ₹23L in 10 years, ₹50L in 15 years, and nearly ₹1 crore in 20 years.
All figures and facts in this article are sourced directly from primary government and regulatory publications — including the Reserve Bank of India, SEBI, EPFO, the Income Tax Department, PFRDA, and IRDAI — and verified before publication. No claim is published from a single source without corroboration.
# How does an SIP work? What ₹10,000/month actually grows to over 10, 15, and 20 years
A Systematic Investment Plan (SIP) is not a product. It is a method — a way of putting a fixed amount of money into a mutual fund at regular intervals, usually every month. The mutual fund itself is the product. This distinction matters because many people assume an SIP is a separate, safer investment. It is not. Your money still goes into whichever mutual fund you choose, with all the risks that come with it.
What an SIP does give you is discipline and a mechanism called rupee cost averaging. Over long periods, these two features can make a meaningful difference to your final corpus.
What exactly happens when you start an SIP?
When you set up an SIP, you authorise your bank to debit a fixed amount — say ₹10,000 — on a specific date every month. That money goes to an Asset Management Company (AMC), which uses it to buy units of the mutual fund scheme you have chosen.
The number of units you receive each month depends on the Net Asset Value (NAV) of the fund on that day. If the NAV is ₹100, you get 100 units. If the market falls and the NAV drops to ₹80 the next month, the same ₹10,000 buys you 125 units. This is rupee cost averaging in action — you automatically buy more units when prices are lower and fewer units when prices are higher, without having to time the market.
SEBI requires all AMCs to offer SIP facilities under the SEBI (Mutual Funds) Regulations, 1996. The minimum SIP amount varies by AMC — some allow as little as ₹100 per month, though ₹500 is the most common practical minimum. Most retail investors start at ₹1,000 or above.
How is the SIP return actually calculated?
The standard formula for the future value of an SIP is:
FV = P × [((1+r)^n − 1) / r] × (1+r)
Where:
- P = monthly investment amount
- r = monthly rate of return (annual rate ÷ 12)
- n = total number of months
For a 12% annual return, the monthly rate r = 12% ÷ 12 = 1% or 0.01.
This formula assumes returns are compounded monthly and that each instalment is invested at the start of the period (an annuity due). Different SIP calculators may use slightly different assumptions, so treat outputs as estimates, not guarantees.
What does ₹10,000/month actually grow to at 12% annual return?
Here is what the formula gives you at a 12% annual return — a figure often used as a long-term proxy for diversified equity mutual fund returns in India, though actual returns will vary.
| Tenure | Amount Invested | Estimated Corpus | Estimated Gain |
| 10 years | ₹12,00,000 | ₹23,23,391 | ₹11,23,391 |
| 15 years | ₹18,00,000 | ₹50,45,760 | ₹32,45,760 |
| 20 years | ₹24,00,000 | ₹99,91,479 | ₹75,91,479 |
A few things to notice:
How does rupee cost averaging actually protect you during a market crash?
Consider what happens during a market correction. Suppose your fund's NAV falls from ₹200 to ₹140 over three months before recovering.
| Month | NAV | ₹10,000 buys | Units accumulated |
| Jan | ₹200 | 50 units | 50 |
| Feb | ₹160 | 62.5 units | 112.5 |
| Mar | ₹140 | 71.4 units | 183.9 |
| Apr | ₹180 | 55.6 units | 239.5 |
Total invested: ₹40,000. Average NAV over the four months: ₹170. But your average cost per unit is ₹40,000 ÷ 239.5 = approximately ₹167 — lower than the simple average NAV. That is rupee cost averaging. By continuing to invest through the dip, you accumulated more units at lower prices.
This does not eliminate risk. If the market never recovers, you still lose money. But it removes the pressure of trying to predict the bottom and invest a lump sum at the right moment — something even professional fund managers rarely get right consistently.
What is a Step-Up SIP and how much more can it build?
A Step-Up SIP (also called a top-up SIP) lets you increase your monthly contribution by a fixed percentage or amount every year. Most AMCs offer this feature, and it aligns well with the reality that salaries tend to rise over time.
Worked example: ₹10,000/month with 10% annual step-up over 20 years
- Year 1: ₹10,000/month
- Year 2: ₹11,000/month
- Year 3: ₹12,100/month
- ...and so on, increasing 10% each year
At a 12% annual return, this step-up SIP produces an estimated corpus of approximately ₹1.9–2.1 crore over 20 years, compared to ₹99.91L with a flat ₹10,000/month SIP.
The total amount invested in the step-up scenario is higher — roughly ₹68–69L over 20 years versus ₹24L for the flat SIP. But the corpus is nearly double. This illustrates two compounding effects working together: your investment amount grows, and returns compound on a larger base each year.
If a 10% annual increase feels steep, even a 5% step-up significantly improves outcomes over two decades.
What is the difference between a Direct plan SIP and a Regular plan SIP?
When you invest in a mutual fund, you can choose between two plan types:
- Regular plan: You invest through a distributor or broker. The AMC pays the distributor a commission, which is embedded in the fund's expense ratio — the annual fee charged as a percentage of your assets.
- Direct plan: You invest directly with the AMC (through their website or app, or through direct platforms). There is no distributor commission, so the expense ratio is lower.
The difference in expense ratio between direct and regular plans is typically 0.5% to 1% per year. On a corpus of ₹50L, that is ₹25,000–₹50,000 per year in additional returns simply by being in the direct plan. Over 20 years, this difference compounds significantly.
AMFI data shows direct plans consistently have lower total expense ratios than their regular counterparts across fund categories.What are the tax rules on SIP returns in India?
SIP returns are taxed based on when you redeem your units, not when you invest. Each monthly instalment is treated as a separate investment with its own holding period.
For equity mutual funds (funds with 65%+ in Indian equities):
- Units held for more than 12 months: Long-Term Capital Gains (LTCG) — taxed at 12.5% on gains above ₹1,25,000 in a financial year (post-Budget 2024)
- Units held for 12 months or less: Short-Term Capital Gains (STCG) — taxed at 20%
For debt mutual funds:
As of April 2023, all debt fund gains are added to your income and taxed at your applicable income tax slab rate, regardless of holding period.
For a long-term SIP in an equity fund, the first ₹1,25,000 of LTCG each year is tax-free. Beyond that, 12.5% applies. This is still relatively tax-efficient compared to fixed deposits, where interest is fully taxable at slab rates.
How do you actually start an SIP in India?
Minimum SIP amounts vary. The AMFI investor education page confirms that some schemes allow SIPs from ₹100/month, while most practical schemes start at ₹500. There is no maximum limit.
Key Takeaways
- An SIP is a mode of investing in mutual funds, not a separate product — your money still carries the risk of the underlying fund.
- ₹10,000/month at 12% annual return grows to approximately ₹23.23L in 10 years, ₹50.46L in 15 years, and ₹99.91L in 20 years — on a total investment of ₹12L, ₹18L, and ₹24L respectively.
- Rupee cost averaging means you automatically buy more units during market dips, lowering your average cost per unit over time.
- A step-up SIP of ₹10,000/month with a 10% annual increase can build a corpus of ₹1.9–2.1 crore over 20 years at 12% returns — nearly double a flat SIP.
- Direct plan SIPs have lower expense ratios than regular plans; the difference of 0.5–1% per year compounds significantly over long tenures.
- LTCG on equity fund SIP redemptions above ₹1,25,000/year is taxed at 12.5% — more tax-efficient than most fixed-income alternatives.
FAQ
Is SIP safe for long-term investing in India?
An SIP in an equity mutual fund carries market risk — the value of your investment can fall in the short term. Over long periods (10+ years), diversified equity funds in India have historically delivered positive inflation-beating returns, but this is not guaranteed. SIP reduces timing risk through rupee cost averaging but does not eliminate market risk.
What happens if I miss an SIP instalment?
Most AMCs do not penalise you for a missed instalment due to insufficient bank balance. Your SIP simply continues the next month. However, repeated missed payments may lead to the SIP being paused or cancelled depending on the AMC's policy. There is no lock-in on most open-ended SIPs — you can stop anytime.
Can I increase my SIP amount later?
Yes. You can either set up a new SIP alongside your existing one or use the step-up SIP feature to automatically increase your contribution each year. Most AMC platforms allow modification without paperwork.
Which is better: SIP or lump sum investing?
If you have a large amount ready and markets are at a reasonable valuation, a lump sum can outperform an SIP because your entire capital compounds from day one. However, most people do not have large lump sums available regularly, and timing the market is difficult. SIP is better suited for regular salary earners who want disciplined, automated investing.
What does XIRR mean on my SIP statement?
XIRR (Extended Internal Rate of Return) is the annualised return on your SIP, accounting for the fact that each monthly instalment was invested at a different time. It is the most accurate measure of your SIP's actual performance. A simple CAGR calculation overstates returns for an SIP because it assumes all the money was invested from day one.
Sources
- AMFI — SIP investor education, Association of Mutual Funds in India
- SEBI (Mutual Funds) Regulations, 1996 (last amended March 2025), Securities and Exchange Board of India
Last verified: May 2026
Content on Ek Crore is for educational purposes only. Nothing here is financial advice. Always consult a SEBI-registered advisor, CA, or qualified professional before making investment or tax decisions.