Why a plain percentage misleads
Suppose you invested ₹10,000 a month for three years — ₹3,60,000 in total — and it is now worth ₹4,50,000. The gain is ₹90,000, which looks like 25%.
It is not 25% a year, and it is not 25% in any useful sense. The first instalment was invested for thirty-six months. The last was invested for one. Dividing the total gain by the total invested treats both as if they had been working equally long, and they plainly were not.
XIRR fixes that. It finds the single annual rate which, applied to each cashflow for exactly the time that cashflow was invested, reproduces the final value. In the example above the answer is somewhere near 15% a year — a very different story from 25%.
What XIRR actually solves
XIRR is the extended internal rate of return. It finds the rate r at which the present value of every cashflow sums to zero:
Σ [ Cashflow_k / (1 + r)^(days_k / 365) ] = 0
Each outflow is negative, the final value is positive, and days_k is the number of days between the first cashflow and that one. There is no closed-form solution — the rate has to be found by iteration, which is exactly what this calculator and a spreadsheet both do under the hood.
The practical consequence: XIRR is sensitive to when money moved, not just how much. Two investors with identical totals and identical end values can have very different XIRRs if one invested earlier than the other.
XIRR and CAGR are not interchangeable
CAGR answers: one amount went in, one amount came out, what was the annual rate? It needs exactly two cashflows.
XIRR answers the same question when there were many cashflows at irregular intervals.
If you made a single investment and redeemed it once, CAGR is the right tool and XIRR returns the same answer. The moment there are instalments, top-ups, partial withdrawals or switches, CAGR cannot represent the position and XIRR is the only honest number.
This is why a fund's published return and your personal return differ. The fund reports what a hypothetical investor who entered on day one would have earned. Your XIRR reports what you earned, given when you actually put money in.
How to use this calculator
- Choose the investment frequency — fortnightly, monthly, quarterly, half-yearly or yearly.
- Set the start date of the first instalment and the maturity date you are measuring to.
- Enter the recurring investment amount paid each period.
- Enter the total maturity amount the investment is now worth.
The calculator builds the full cashflow series, then solves for the rate that fits it. It also shows the total invested and the absolute return, so you can see the gap between the two measures for yourself.
Reading the result
A negative XIRR means the position is worth less than what went into it. A very large XIRR over a short period is usually a measurement artefact rather than a triumph — annualising a few weeks of gain extrapolates it across a year that has not happened.
Compare XIRR against an alternative you could actually have chosen: a fixed deposit rate, an index fund, or the fund's own benchmark. A number without a comparison does not tell you whether the investment was worth making.