Investor Corner/Building and judging a portfolio/Performance Measurement
3.2.2 XIRR
XIRR, or Extended Internal Rate of Return, is the correct way to measure return when money moves in and out at different times, exactly as happens with SIPs, top-ups and partial withdrawals.
Why a simple average falls short
If you invested different amounts on different dates through a SIP, a simple average of each instalment's individual return does not correctly reflect your actual overall return, because it fails to account for the fact that later instalments had less time to grow than earlier ones. XIRR solves this properly by considering the exact date and size of every single cash flow, in and out, and solving for the single annualised rate that makes them all consistent.
XIRR (Extended Internal Rate of Return) is the annualised return that accounts for the exact dates and amounts of every cash flow in and out of an investment. Unlike CAGR, which assumes a single lump sum, XIRR handles the reality of SIP investing where money enters the portfolio at different times and in different amounts. It solves for the single discount rate that sets the net present value of all cash flows (contributions, withdrawals, current value) to zero.
For a SIP running over several years, each monthly instalment entered at a different NAV and has had a different amount of time to compound. The first instalment has the longest runway; the most recent has barely had time to earn any return. XIRR correctly weights each instalment by its duration and produces the true annualised return that the investor actually experienced, not an approximation.
What XIRR is really answering
XIRR answers a very specific, very useful question: given exactly when and how much money went in, and exactly when and how much came out or is worth today, what constant annual rate of return would explain that entire pattern? It is the standard measure for anything involving irregular cash flows, which describes most real-world SIP investing rather well.
Computing XIRR by hand is impractical for a portfolio with dozens of SIP transactions across multiple funds. Spreadsheet functions (XIRR in Excel or Google Sheets) can do it given a column of dates and a column of corresponding cash flows (negative for investments, positive for redemptions, with the current portfolio value as a final positive entry). Portfolio tracking tools compute it automatically. The result is a single percentage that honestly answers: what annualised return did I actually earn on my money, given exactly when each rupee was invested?
XIRR can differ significantly from the fund's reported CAGR. If most of your SIP instalments happened to fall during a period of low NAVs (you bought cheaply), your personal XIRR will be higher than the fund's CAGR. If most instalments fell during a period of high NAVs, your XIRR will be lower. This is why two investors in the same fund can have different personal returns depending on when they invested, which is precisely the information that XIRR captures and CAGR does not.
Where you will encounter it
Any mutual fund tracking tool worth using should be computing XIRR for you automatically, since calculating it by hand for a portfolio with dozens of SIP instalments across multiple funds is genuinely impractical without dedicated software. It is the single most important return figure for any SIP investor to actually understand and trust.
How PriLytics helps. PriLytics computes accurate XIRR for every fund and for your whole portfolio, based on the exact dates and amounts from your real transaction history. See how returns are calculated.
For portfolio-level analysis, XIRR can be computed across all funds together, treating the entire portfolio as a single investment with multiple inflows and outflows. This gives the overall portfolio return, which is the number that matters most for evaluating whether your financial plan is on track. Fund-level XIRR is useful for comparing individual holdings; portfolio-level XIRR is the number that answers the question that actually matters: is my money growing fast enough to meet my goals?