Question 1

What is XIRR and how is it different from IRR?

Accepted Answer

XIRR is the annualized rate of return for a series of cash flows that happen on irregular, actual dates — unlike standard IRR, which assumes cash flows land on evenly-spaced periods (e.g. exactly once a year). XIRR uses the real day-count gap between each cash flow and the first one, which matters for real project payments, staggered equipment financing draws, or retention releases that rarely fall on tidy anniversaries.

Question 2

When should a contractor use XIRR instead of IRR?

Accepted Answer

Whenever payments or receipts don't land on regular annual (or other fixed) intervals — a client paying in irregular instalments, equipment financing with an uneven drawdown-and-repayment schedule, or retention released at project-specific milestones rather than fixed dates. IRR's even-interval assumption understates or overstates the real return whenever actual dates are irregular.

Question 3

Why does XIRR sometimes show "not found"?

Accepted Answer

Like IRR, XIRR only exists where the discounted cash flow total actually crosses zero somewhere in the search range. A cash flow series that never breaks even, or is profitable at every rate, has no meaningful XIRR — this calculator reports that honestly instead of returning a number that doesn't actually solve the equation.

XIRR Calculator

Cash Flows (date + amount; first flow is usually a negative outflow)

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