CAGR vs XIRR: which one should you use for SIP returns?
CAGR and XIRR both give you a single annual growth percentage, which is exactly why they get confused for each other — but they're built for different shapes of cash flow, and using the wrong one on a SIP gives you a misleading number.
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What CAGR measures
CAGR (Compound Annual Growth Rate) answers one specific question: if a single amount grew from a starting value to an ending value over a certain number of years, at what constant annual rate would it have had to grow? It assumes exactly one cash flow in (at the start) and one cash flow out (at the end) — nothing in between.
That makes CAGR the right tool for a lump-sum investment, or for comparing a fund's NAV at two points in time. It smooths out the year-to-year bumps into a single, easy-to-compare number.
What XIRR measures
XIRR (Extended Internal Rate of Return) is built for exactly the situation CAGR can't handle: multiple cash flows, of different amounts, on different (possibly irregular) dates — which is precisely what a SIP is, since every monthly installment is its own separate cash flow going in at its own date.
XIRR finds the single annual rate that, if applied consistently to every one of those individual cash flows from its own date, would produce your actual final corpus. It's the same underlying idea as CAGR — one constant annual rate — just generalized to handle any pattern of cash flows instead of only one in and one out.
Why applying CAGR to a SIP gives a misleading number
If you take your total SIP contributions as a single lump sum and your final corpus as the end value, then compute CAGR over the investment period, the result is technically a number but not a meaningful "return" — it treats money that was actually invested gradually, with most of it going in only in the later years, as if it had all been invested on day one. That systematically understates how well your money actually performed, because the early years had little capital invested and therefore little time to compound relative to what CAGR assumes.
This is the single most common SIP return mistake: comparing a fund's advertised CAGR (typically the fund's lump-sum trailing return) directly against your own SIP's outcome, then concluding the fund underperformed, when actually you're comparing two different kinds of numbers.
Which to use, in practice
Use CAGR for: a lump-sum investment, comparing a fund's historical NAV growth, or any single-entry, single-exit scenario (this site's CAGR calculator is built for exactly that). Use XIRR for: your own SIP's actual return, since it correctly accounts for every installment's own date and amount.
Mutual fund fact sheets typically publish CAGR (or "trailing returns") because it describes the fund's own performance independent of how any individual investor timed their contributions — it's a property of the fund, not of your specific SIP. Your personal SIP return is a property of your specific cash flows, which is what makes it an XIRR question, not a CAGR one.
Not accurately. CAGR assumes a single lump-sum investment, so applying it to a SIP's multiple monthly contributions gives a distorted number. Use XIRR instead, which is designed for exactly this pattern of cash flows.
Why do mutual fund fact sheets show CAGR instead of XIRR?
Fact sheets are describing the fund's own performance (its NAV growth over time), which is a single-entry, single-exit measurement independent of any individual investor's SIP dates — that's a CAGR question, not an XIRR one.
Does a higher XIRR always mean a better-performing fund?
Not necessarily — your XIRR also reflects when you happened to invest, not just the fund's underlying quality. Two investors in the same fund with different SIP start dates or contribution patterns can end up with different XIRRs.
