CAGR vs XIRR — Why Comparing Your SIP Returns to a Friend's Lumpsum Is Misleading
TL;DR
- CAGR (Compound Annual Growth Rate) measures returns on a single investment — one amount in, one amount out
- XIRR (Extended Internal Rate of Return) measures returns when multiple investments are made at different times — which is exactly what a SIP does
- Using CAGR to evaluate a SIP gives you the wrong answer, often making good SIPs look like they underperformed
- The same SIP that shows 7% "CAGR" can show 13% XIRR — a 6 percentage point difference from the same data
- Most mutual fund apps (Groww, ET Money, Zerodha Coin) calculate XIRR automatically — but you should understand what you are looking at
The Confusion That Starts Most of These Conversations
You have been doing a ₹10,000 monthly SIP for 5 years. Your friend put ₹6 lakh as a lumpsum in the same fund 5 years ago. You both look at your returns. His statement shows 12% CAGR. Your statement says something like "total invested ₹6 lakh, current value ₹8.45 lakh" and you calculate a 7% "return."
You feel like you underperformed. You wonder if SIP was the right choice.
The problem is not the SIP. The problem is the calculation. You cannot compare a lumpsum CAGR to a SIP return using the same formula.
What CAGR Actually Measures
CAGR tells you the constant annual rate at which a single investment would have needed to grow to go from its starting value to its ending value.
Formula: CAGR = (Final Value / Initial Value)^(1/years) − 1
Example: You invest ₹6 lakh on January 1, 2021. By January 1, 2026, it is worth ₹10.57 lakh.
CAGR = (10,57,000 / 6,00,000)^(1/5) − 1 = 12%
This is clean and correct for a lumpsum. One investment date, one exit date, one number.
The problem: CAGR assumes all your money was invested on day one and sat there for the entire period. A SIP does not work like that. Your first instalment was invested 60 months ago. Your last instalment was invested last month. Each has had a different amount of time to compound. Treating them all as a single investment is mathematically wrong.
What XIRR Actually Measures
XIRR calculates the annualised return across multiple cash flows happening at different dates. It answers the question: what single annual rate, applied to each investment from its specific date of entry, explains the total outcome?
This is precisely what a SIP needs. Each monthly instalment is a separate investment with its own start date. XIRR accounts for this correctly.
Here is the same scenario compared properly:
| Lumpsum | SIP | |
|---|---|---|
| Amount invested | ₹6,00,000 (Jan 2021) | ₹10,000/month (60 instalments) |
| Total invested | ₹6,00,000 | ₹6,00,000 |
| Final value | ₹10,57,000 | ₹8,45,230 |
| Correct metric | CAGR | XIRR |
| Return | 12.0% | 13.24% |
The SIP actually outperformed the lumpsum on its correct metric — because it bought heavily during the COVID crash of March 2020 when NAVs were low, and those cheap units drove the final corpus. But if you had used CAGR on the SIP, you would have calculated 7.1% and concluded wrongly that the SIP failed.
Why the "Wrong CAGR" Calculation Is So Common
Many investors and even some financial portals calculate SIP returns like this:
Wrong CAGR = (Final Value / Total Invested)^(1/n) − 1
This treats all your monthly SIP instalments as if they were a single lumpsum invested on the first day. Your 60th instalment — which has only been invested for one month — gets credited with 5 full years of compounding it never had. The result is a number that understates your actual return.
This is why you should never take the CAGR number from a SIP statement at face value. If it shows CAGR, it is either wrong or it is showing you something else (like the fund's own 5-year lumpsum return, not your SIP return).
How to Calculate XIRR Yourself
You do not need to do the underlying maths — it is iterative and impractical by hand. Use Excel or Google Sheets.
In Google Sheets:
Create two columns. Column A: dates. Column B: cash flows.
Enter each SIP date as a negative number (money going out from you). Enter your final portfolio value as a positive number on today's date (money coming back to you).
A (Date) B (Cash Flow)
01-01-2021 -10000
01-02-2021 -10000
01-03-2021 -10000
...
01-12-2025 -10000
11-04-2026 +845230 ← current portfolio value
Then in any empty cell, type: =XIRR(B:B, A:A)
The result — 13.24% in this example — is your actual annualised return.
If you have a large SIP history and do not want to enter every date manually, most mutual fund platforms and portfolio trackers do this automatically. ET Money, Groww, Zerodha Coin, Parag Parikh's investor portal, and most AMC websites show XIRR. If yours shows "absolute returns" or a suspiciously round CAGR number for a SIP, it is likely using the wrong calculation.
When XIRR Is Higher Than the Fund's CAGR
This happens when markets fell during your SIP period and then recovered. The March 2020 COVID crash is the clearest example. If your SIP was running through early 2020, you accumulated a large number of units at deeply discounted NAVs (Nifty at 8,000-9,000 levels). When markets recovered, those cheap units drove your returns significantly above what someone who invested a lumpsum before the crash would have earned.
In this scenario, your SIP's XIRR can be meaningfully higher than the fund's 5-year lumpsum CAGR — even though you invested the same total amount.
When XIRR Is Lower Than the Fund's CAGR
This happens in a sustained, uninterrupted bull market. If the Nifty rises steadily from 12,000 to 25,000 over 5 years without significant corrections, a lumpsum invested at 12,000 captures the entire gain. A SIP invests at every price point along the way — including the expensive ones — and accumulates fewer cheap units. The lumpsum CAGR can exceed the SIP's XIRR in this environment.
The period from 2014-2017 during the early Modi rally is an example where lumpsums outperformed SIPs on an annualised basis.
Neither outcome is wrong — it is simply what each instrument is designed for. SIPs are designed for volatility. Lumpsums are designed for a single point-in-time decision with a long horizon.
The Practical Implication for How You Read Your Portfolio
When you look at your mutual fund statement or portfolio app:
If it shows XIRR or annualised returns for a SIP — that is the correct number. Compare it to the fund's lumpsum CAGR for the same period to get a sense of whether your SIP benefited from or was hurt by market timing.
If it shows absolute returns (like "your investment grew 45%") — divide by the number of years to get a rough annualised sense, but remember this is still not XIRR and is not comparable to CAGR.
If it shows CAGR for a SIP — treat it with suspicion. Calculate XIRR in Google Sheets using your actual dates to verify.
For your overall portfolio, the number that matters is your portfolio XIRR — the annualised return across all your investments, all dates, all amounts. This is what tells you whether your investing strategy is working.
Use the SIP Calculator to model expected corpus at a target XIRR and see what monthly investment you need to reach your goal.
Frequently Asked Questions
My SIP portfolio shows 8% returns but my friend's lumpsum shows 14%. Did I make a mistake?
Not necessarily. First, verify that your 8% is XIRR and not a misleading CAGR calculation — if it was calculated as (final value/total invested)^(1/years)−1, it understates your real return. Second, if it is genuine XIRR, the comparison also depends on time period. A lumpsum invested at the right moment in a bull market will outperform a SIP in that same period. Over a longer horizon with volatility, SIP XIRR and lumpsum CAGR tend to converge. Verify your number using the Google Sheets method above.
How do I calculate XIRR if I have been doing a SIP for 7 years with hundreds of transactions?
Download your account statement from your AMC or platform as a CSV or Excel file. Most AMCs provide a transaction history export. Import it into Google Sheets, format the dates in column A and amounts in column B (negative for purchases, positive for current value on today's date), and run =XIRR(B:B, A:A). Alternatively, platforms like ET Money, Groww, and Zerodha Coin automatically calculate and display XIRR for your full portfolio history.
What is a good XIRR for a SIP in an equity mutual fund?
Over a 10-year period, a well-run diversified equity fund SIP should deliver 11-15% XIRR depending on market conditions during that period. For SIPs that ran through significant corrections (2008, 2020), XIRR tends to be at the higher end because of cheap units accumulated during downturns. Consistent XIRR above 12% over a 10-year SIP period is a strong outcome. Below 8% over 10 years in an equity fund would suggest something is wrong — either the fund underperformed badly or there were significant interruptions to the SIP.