Reviewed by Finin2min Editorial Desk · Last reviewed 11 August 2026
Solve the annual discount rate that makes the net present value of irregular yearly project cash flows equal to zero.
Enter project cash flows
Annual IRR
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Cash-flow sign changes
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Multiple sign changes can produce multiple or misleading IRRs.
How This Is Calculated
IRR is the discount rate at which the Net Present Value of a series of cash flows equals zero — solved numerically since it generally can't be isolated algebraically. A project with IRR above the required rate of return (hurdle rate) is generally considered attractive; below it, generally not.
Frequently Asked Questions
How is IRR different from NPV?
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NPV gives an absolute rupee value of a project at a specified discount rate. IRR instead solves for the discount rate itself — the rate at which NPV would be exactly zero — giving a percentage return figure that can be compared against a hurdle rate or across projects of different sizes.
Can a project have more than one IRR, or no valid IRR?
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Yes — if cash flows change sign more than once (e.g., positive, then negative, then positive again), the IRR equation can have multiple valid roots or none at all, which is why this calculator flags the number of sign changes — multiple sign changes make IRR interpretation unreliable and NPV a more robust metric to rely on instead.
IRR is the discount rate that sets NPV to zero for the entered cash-flow sequence. Multiple sign changes can create multiple IRRs, and some cash-flow patterns have no meaningful IRR.
Always read IRR together with NPV at a chosen hurdle rate and the actual dates/timing convention. A high IRR on a small or short project can still create less value than a lower-IRR alternative.
Input integrity
Use source documents rather than approximate memory.
Confirm period, units, tax regime/category and sign conventions.
Test zero, threshold and just-above-threshold cases where relevant.
Output interpretation
Separate arithmetic output from legal eligibility/classification.
Preserve assumptions and the official-source date.
Use the linked detailed guide for exceptions and evidence.
Scope: Computes the Internal Rate of Return (IRR) — the discount rate at which the net present value of a series of cash flows equals zero — for an investment with an initial outlay and subsequent cash inflows/outflows.
Calculation logic
Set up the cash flow series with the initial investment as a negative value (at time 0) and each subsequent period's net cash flow as entered.
Solve for the rate r such that: Σ (CFt ÷ (1 + r)t) = 0 across all periods t, using an iterative numerical method (e.g., Newton-Raphson or bisection) since IRR has no closed-form algebraic solution for more than 2 cash flows.
Where cash flows change sign more than once, flag that multiple IRRs may exist and the result should be interpreted alongside NPV, not in isolation.
Inputs and assumptions
Assumes cash flows occur at the end of each discrete period entered (annual, unless otherwise specified) — the calculator does not adjust for mid-period or irregular-date cash flows unless dates are provided.
IRR assumes interim cash flows are reinvested at the IRR itself — a known limitation of the metric compared to Modified IRR (MIRR).
Exclusions and edge cases
Does not compute MIRR (which assumes reinvestment at a specified rate rather than at IRR itself) unless that option is separately provided.
Non-conventional cash flow patterns (multiple sign changes) can produce multiple mathematically valid IRRs — the tool flags this rather than silently picking one.
Sources
No external regulatory source applies — this is a general financial formula, not a statutory computation.
Review status: reviewed and approved by CA Nikhil Gupta on 18 July 2026.