What is a SIP Calculator?
Priya, 28, earns ₹65,000 a month in Bangalore. She wants to build ₹1 crore in 15 years. Her colleague says "start a SIP of ₹15,000, 12% return milega." But Priya has no idea — will ₹15,000 be enough? Or does she need ₹20,000? Enter three numbers into this SIP calculator: ₹15,000 monthly, 12% expected return, 15 years. Result: ₹75.7 lakh. She's short by ₹24 lakh. She increases the SIP to ₹20,000 — now it crosses ₹1 crore in the same period.
That's the whole job of a SIP calculator. It takes your monthly investment, expected return, and time horizon — and shows you exactly how much your money grows. Not a rough estimate. The exact number, based on compound interest math.
How to Use This SIP Calculator
Three inputs, three outputs. That's it.
Monthly Investment: The amount you want to invest every month. If you're starting small, ₹500 is a valid input. If you're investing ₹5,000 a month, enter 5000. SIPs work best when the amount is fixed and automatic — set up an ECS mandate at your bank, and money moves on a fixed date without you thinking about it.
Expected Return: The annual rate you expect from your mutual fund. Equity funds historically return 10-14% over long periods. Debt funds are lower, 6-8%. A balanced portfolio might average 10-11%. Enter the rate as a percentage — 12, not 0.12. Be honest here — most users overestimate to make their numbers look better. 11-12% is a realistic long-term assumption for equity mutual funds in India.
Duration: Time in years. This is the most powerful variable — doubling from 10 to 20 years doesn't double the result, it multiplies it by nearly four times. Enter 10, 15, or 25 depending on your goal.
The output shows three things: total amount you invested, estimated returns, and final corpus value. Most users focus only on the final value and skip the "total invested" number — which is the real story. If you invest ₹30 lakh over 20 years and it becomes ₹90 lakh, the question is whether that ₹60 lakh gain justifies the ₹30 lakh you gave up over two decades.
The SIP Formula (And Why It Beats Lumpsum in Most Cases)
The formula is: FV = P × ((1+i)^n − 1) ÷ i × (1+i)
Where P is monthly investment, i is the monthly rate of return (annual rate ÷ 12 ÷ 100), and n is the number of monthly instalments.
Why does SIP work so well? Because each instalment starts compounding from the day it's invested. The first month's ₹5,000 compounds for all 120 months. The second month's ₹5,000 compounds for 119 months. The last instalment barely compounds at all. The formula adds up all these individual growth curves into a single future value.
This is why SIP usually beats lumpsum in volatile markets. In lumpsum, if you invest ₹6 lakh on a bad day and the market drops 20% the next month, all your money is down 20%. In SIP, you bought at various prices — some high, some low — and the average cost per unit is lower than if you'd invested everything on the worst day.
Real Examples at Different Scales
Example 1 — Starting Small (₹2,000/month, 12%, 10 years)
Total invested: ₹2,40,000. Estimated returns: ₹2,24,000. Final corpus: ₹4,64,000. This is the reality check most people need — you don't double your money in 10 years, you nearly double it. A ₹2,000 SIP is a great habit-starter, but it won't build serious wealth in a decade.
Example 2 — Serious Saver (₹10,000/month, 12%, 15 years)
Total invested: ₹18,00,000. Estimated returns: ₹32,45,000. Final corpus: ₹50,45,000. Notice the ratio — you invested ₹18 lakh, you got back ₹50 lakh. The gain (₹32 lakh) is nearly twice your total investment. This is where compounding starts to feel real.
Example 3 — Goal-Based (₹25,000/month, 11%, 20 years)
Total invested: ₹60,00,000. Estimated returns: ₹1,64,00,000. Final corpus: ₹2,24,00,000. ₹2.24 crore from a ₹25,000 monthly SIP. This is what child education or retirement planning looks like. A 20-year horizon is where SIP becomes genuinely life-changing — the returns (₹1.64 cr) are 2.7x the investment (₹60 lakh).
Example 4 — Step-Up Reality (₹15,000/month increasing 10% yearly, 12%, 15 years)
Total invested: ₹57,00,000 (roughly). Final corpus: ₹1,32,00,000. The SIP calculator assumes a fixed monthly amount. But most real investors increase their SIP every year as salary grows. A step-up SIP of 10% yearly beats a fixed SIP of the same starting amount by 40-50% over 15 years.
Common Mistakes in SIP Calculation
- Assuming 15-18% returns. Equity funds occasionally hit these numbers in bull markets, but no fund delivers 15% consistently for 20 years. If your plan only works at 15%, it's not a plan — it's a hope. Use 11-12% for realistic planning.
- Not accounting for expense ratio and exit load. Mutual funds charge 0.5-1.5% annually as expense ratio, and 1% exit load if you withdraw within a year. A fund showing 12% returns before expenses actually delivers 10.5-11.5% to you. Enter the net expected return, not the gross.
- Stopping SIP during market falls. The whole point of SIP is that when markets fall, your fixed amount buys more units. Users who pause their SIP during a crash lock in the losses of the existing units and miss the recovery upside.
- Ignoring LTCG tax on redemption. Equity mutual fund gains above ₹1.25 lakh per year are taxed at 12.5% (LTCG, as of 2025). If your SIP calculator shows ₹50 lakh returns, real in-hand gains are lower after tax. Plan for a 10-12% reduction on equity gains.
When This SIP Calculator Doesn't Apply
SIP calculators assume fixed monthly investment, fixed rate of return, and no withdrawals. Real life is messier:
- Step-up SIPs. If you increase your SIP amount every year (10% is common), this calculator underestimates the final corpus significantly.
- Variable returns. Markets don't deliver 12% every year — they deliver 30% one year, minus 15% the next. The final average may be 12%, but the journey is volatile.
- Partial withdrawals. If you withdraw money in between (for a house down payment, wedding), the corpus shrinks and compounding on that portion stops.
- Goal-based calculations with inflation. If your goal is "₹1 crore in today's money," the calculator's ₹1 crore won't cut it — 20 years of 6% inflation makes ₹1 crore feel like ₹31 lakh.
For step-up or goal-based planning, talk to a SEBI-registered investment advisor. This calculator gives you a solid base estimate.
Frequently Asked Questions
Is SIP better than lumpsum investment?
In volatile markets, SIP wins because it averages your purchase price across various market levels. In a steadily rising market, lumpsum wins because your entire money compounds from day one. For most retail investors without market timing skill, SIP is the safer default. Data from Indian equity markets over the last 20 years shows SIP beating lumpsum in roughly 60-70% of 10-year rolling periods.
What return should I assume for equity mutual funds?
For large-cap equity funds, use 10-11%. For mid-cap and small-cap funds, use 11-12% but expect higher volatility. Don't assume 15% — that's not a realistic long-term number and will lead to disappointment. The Nifty 50 has delivered roughly 11-12% CAGR over the last 20 years.
Can I pause my SIP without penalty?
Yes. SIPs are not contracts — you can pause, modify, or stop them anytime without penalty. There's no exit load on pausing (exit load only applies if you redeem units within the lock-in period, usually 1 year). Pause during a cash crunch, resume when you can.
What is the minimum SIP amount?
Most mutual funds allow SIPs starting at ₹500 per month. Some allow ₹100. The amount doesn't matter as much as the consistency — a ₹500 SIP maintained for 20 years beats a ₹5,000 SIP maintained for 2 years and then abandoned. Start small, stay consistent, increase yearly.
Does SIP work for debt funds too?
Yes, but the returns are lower. Debt fund SIPs make sense for goals 3-5 years away — like a car down payment or a short-term goal. Expect 6-8% returns. Equity SIPs are for goals 7+ years away. Don't mix the two — a 3-year goal funded by equity SIPs is asking for trouble if the market drops in year 2.
What is a step-up SIP and should I use one?
A step-up SIP (or top-up SIP) automatically increases your monthly investment by a fixed percentage every year — usually 5-10%. If your income grows 8% annually, your SIP should too. A ₹10,000 SIP with 10% yearly step-up becomes ₹23,600 in 10 years and delivers significantly more than a flat ₹10,000 SIP. If your fund house offers this feature, enable it.
Why This Calculator Exists
SIP math isn't intuitive. The difference between ₹10,000 and ₹12,000 a month feels small today but becomes ₹15-20 lakh over 20 years. The difference between 10 years and 15 years feels like 5 years but becomes 3x the corpus. This calculator shows you the actual numbers so you can set realistic goals. No signup, no ads in between, no confusion about which rate to use.
Last updated: 18 September 2026