How SIP Works: A Simple Guide With Calculator For 2026

Last Updated: May 22, 2026

Table of Contents

How SIP Works

You Keep Meaning to Invest. SIP Invests for You.

Meet Rohan. Age 27. Every month he promises himself he will invest — but by the 15th, the money is gone on bills and things he did not need.

Now meet Kavita. Same age. Five years ago she set up a ₹3,000 per month SIP on her salary date and never thought about it again. Today her portfolio is worth ₹2,44,000 on a total investment of ₹1,80,000 — ₹64,000 created without any effort after the first setup.

That is SIP. Not a fund. Not a product. A method — the simplest and most consistent way for Indian retail investors to build wealth.

India’s SIP data as of January 2026 (Source: AMFI)

Active SIP Accounts	Monthly Inflows	Total SIP AUM	YoY Growth
9.92 crore	₹31,000 crore	₹16.36 lakh crore	+17%

What Is a Systematic Investment Plan (SIP)?

SIP is a simple instruction to your bank: automatically send a fixed amount to your chosen mutual fund on a specific date every month. Once set up, it runs on its own — no logging in, no market tracking, no remembering.

SIP is not a mutual fund. It is a method of investing in one — just like an EMI is not a loan but a method of repaying one. The difference: an EMI builds someone else’s wealth. A SIP builds yours.

How Does a SIP Work? — 4 Steps

Step 1 — Choose a fund and amount. Pick a mutual fund scheme. Minimum is ₹500/month for most funds.

Step 2 — Auto-debit runs on your chosen date. Your bank deducts the fixed amount automatically via a NACH mandate. No action needed.

Step 3 — Units are allocated at that day’s NAV. NAV (Net Asset Value) is the per-unit price of the fund. When NAV is high, your SIP buys fewer units. When it falls, you buy more. This automatic buying at different price levels is called Rupee Cost Averaging — it turns market dips into your advantage.

Step 4 — Wealth compounds over time. More units each month, growing in value over years. The longer you stay invested, the more powerful the effect.

Quick example — ₹5,000 SIP over 3 months:

Month	NAV	Units Bought	Total Units
Month 1	₹100	50	50
Month 2 (market dips)	₹80	62.5	112.5
Month 3 (partial recovery)	₹90	55.6	168.1

Invested: ₹15,000 → Portfolio value at ₹90 NAV: ₹15,125 — in profit despite the market still being below where it started.

SIP Calculator — The Formula

M = P × {[(1 + r)^n – 1] / r} × (1 + r)

M = final amount | P = monthly SIP | r = monthly return rate (annual ÷ 12) | n = total months

Example — ₹5,000/month, 10 years, 12% assumed annual return:

r = 0.01 | n = 120 → Estimated value: ₹11,61,695 on ₹6,00,000 invested

Wealth created purely through compounding: ₹5,61,695

12% is illustrative based on long-term Nifty 50 historical averages. Returns are market-linked, neither fixed nor guaranteed. Actual results will vary.

Use the free official calculator at amfiindia.com

How Long You Stay Invested Changes Everything

Duration	Total Invested	Estimated Value (12% CAGR)	Multiplier
5 years	₹3,00,000	₹4,08,348	1.4x
10 years	₹6,00,000	₹11,61,695	1.9x
20 years	₹12,00,000	₹49,95,740	4.2x
30 years	₹18,00,000	₹1,76,49,569	9.8x

Same ₹5,000/month SIP. The only variable is time.

The 30-year investor put in ₹18 lakh and received back nearly ₹1.76 crore — not through luck, but through consistency. Every year you delay starting costs more than the year before.

SIP vs Lump Sum — When to Use Which

For most salaried investors in 2026, SIP is generally more suitable for most salaried investors

— it removes timing risk, automates discipline, and benefits from falling markets through Rupee Cost Averaging.

Lump sum makes sense only for a one-time windfall — bonus, inheritance, or property sale. Even then, the smartest move is a Systematic Transfer Plan (STP): park the full amount in a liquid fund, then transfer a fixed amount monthly into an equity fund. Best of both worlds.

Types of SIP — Briefly

Regular SIP — Fixed amount, fixed date. Best for most people.
Step-Up SIP — Amount increases automatically each year. If your salary grows 10%, increase your SIP by 10% too. A ₹5,000 SIP stepped up 10% annually can produce over ₹1.64 crore in 20 years vs ₹50 lakh from a fixed SIP — same starting amount, dramatically different outcome.
Perpetual SIP — No end date. Runs until you stop it. Great for long-term goals.
Flexible SIP — Vary the amount each month. Useful for freelancers and variable income earners.

How to Start Your First SIP — 5 Steps

Before you start: Keep 6 months of expenses in savings first. Only SIP with money you will not need for 5+ years.

Step 1 — KYC (one time, 10 minutes): Need Aadhaar + PAN. Complete free at MF Central — AMFI’s official KYC portal.

Step 2 — Choose your fund: For beginners — a Nifty 50 Index Fund (lowest cost, tracks India’s top 50 companies) or a Flexi Cap Fund (manager handles allocation). Check data at amfiindia.com.

Step 3 — Choose a platform: Groww, Zerodha Coin, Paytm Money, or directly on the AMC website for direct plans (0.5–1% lower fees than regular plans — adds up to lakhs over 20 years).

Step 4 — Set amount and date: Even ₹500 works. Set the date 3–5 days after your salary credit.

Step 5 — Activate and forget: Your platform sets up the NACH mandate. SIP runs automatically from next month. Check your portfolio once a quarter.

How SIP Gains Are Taxed (ITA 2025, amended by Finance Act, 2026)

Each SIP instalment is treated as a separate investment with its own holding period.

Gain Type	Holding Period	Tax Rate	Exemption	Section
LTCG	More than 12 months	12.5%	₹1,25,000/year	Sec 198, ITA 2025
STCG	12 months or less	20%	None	Sec 196, ITA 2025

For ELSS SIPs, each instalment has a 3-year lock-in per SEBI regulations, after which LTCG rules apply. Verify current income tax rates at incometaxindia.gov.in.

Key Takeaways

SIP = automatic monthly investment in a mutual fund. Set once, runs forever.
Falling markets help SIP investors — more units bought cheaply (Rupee Cost Averaging).
Time matters more than amount. ₹500/month for 20 years beats ₹5,000/month for 3 years.
STCG: 20% (Sec 196, ITA 2025) | LTCG: 12.5% above ₹1.25L (Sec 198, ITA 2025).
Always build your emergency fund before starting equity SIPs.

Frequently Asked Questions

Q1: What is the minimum SIP amount?

₹500/month for most funds; ₹250 under AMFI’s Chhoti SIP initiative. Consistency matters more than amount.

Q2: Can I stop a SIP anytime?

Yes, no penalty — except ELSS SIPs have a 3-year lock-in per SEBI rules. Stopping does not redeem your units; money stays invested until you withdraw.

Q3: Is SIP better than FD?

Over 5+ years, equity SIPs have historically outperformed FDs. But mutual funds carry market risk; FDs are fixed and guaranteed. Choose based on your time horizon and risk comfort.

Q4: What if markets crash while I’m SIPing?

Keep going — your SIP buys more units at lower prices. Investors who paused in 2008 and March 2020 missed the entire recovery.

Q5: Which is the best SIP plan in 2026?

For beginners: a Nifty 50 Index Fund or Flexi Cap Fund. No single fund suits everyone — verify fund data at amfiindia.com and invest based on your own goal and risk profile.

Conclusion

SIP is discipline turned into automation. Decide once — the fund, the amount, the date — and it works without you. The best SIP is not the one with the highest projected return. It is the one you start today and never stop.

Start small if you must. But start.

Official References

Income Tax Act, 2025 — incometaxindia.gov.in (Sections 196, 198, 2(101))
SEBI (Mutual Funds) Regulations, 1996
AMFI Industry Data

Author

CA Ajay Khandelwal is a Chartered Accountant and financial expert with over 21 years of experience in taxation, compliance, and business advisory. As a key expert at AspirixWriters, he provides practical insights on income tax, financial planning, and regulatory matters, helping readers make informed financial decisions.

Author profile CA. Ajay Khandelwal

Disclaimer:

For educational purposes only — not personal financial or tax advice. Mutual fund investments are subject to market risks; returns are not guaranteed. Tax laws may change — For personalised investment advice, consult a SEBI-registered Investment Advisor (RIA) or Mutual Fund Distributor (MFD). Find a registered advisor at: sebi.gov.in