IRR Calculator
Calculate internal rate of return, NPV, MIRR, profitability index and payback for equal-period investment or project cash flows.
Last Updated: July 23, 2026Calculate IRR from Equal-Period Cash Flows
Use negative values for investments or costs and positive values for receipts. Keep every row one equal period apart.
| Period | Amount | Description, optional | Remove |
|---|
Enter equal-period cash flows, then select Calculate IRR.
| Annual discount rate | NPV | Decision signal |
|---|
IRR assumes equal spacing between cash-flow rows. For cash flows on irregular calendar dates, use XIRR. A positive NPV at your hurdle rate is often more useful than IRR alone when comparing projects of different size.
What Is Internal Rate of Return?
Internal rate of return, or IRR, is the discount rate that makes the net present value of a cash-flow schedule equal to zero. It converts several periodic costs and receipts into one return rate. Businesses use IRR to evaluate projects, equipment purchases, property developments, private investments and other decisions with cash flows spread over time.
IRR is a money-weighted measure. The size and position of every cash flow affect the answer. A project with a large early receipt might show a stronger IRR than one that returns the same total cash later. This timing adjustment makes IRR more informative than adding all inflows and subtracting all outflows.
This calculator assumes equal spacing between rows. If annual frequency is selected, Period 1 occurs one year after Period 0. With quarterly frequency, each row is one quarter apart. Use the XIRR Calculator when actual calendar dates are irregular.
How to Use This IRR Calculator
- Select one currency for the complete project. The selection changes formatting, not the calculation.
- Select monthly, quarterly, half-yearly or annual frequency. Every row must represent one equal interval.
- Enter the annual hurdle rate. This is your required return or cost of capital for NPV comparison.
- Enter annual finance and reinvestment rates for MIRR. Finance rate applies to negative cash flows. Reinvestment rate applies to positive cash flows.
- Enter Period 0 as a negative amount when it represents the initial investment.
- Add later costs as negative amounts and receipts as positive amounts. Add a terminal or resale value to the final period when relevant.
- Add or remove periods as needed. The tool supports 2 to 50 cash-flow rows.
- Select Calculate IRR. Review IRR, NPV, MIRR, profitability index, payback and discount-rate scenarios together.
Use expected net cash flows after operating costs and working-capital changes when assessing a project. Keep financing cash flows separate when the hurdle rate already reflects financing cost, unless your analysis method specifically requires them.
IRR Formula and Calculation Method
0 = C0 + C1 ÷ (1 + r) + C2 ÷ (1 + r)2 + ... + Cn ÷ (1 + r)n
- C0 is the cash flow at Period 0.
- Ct is the cash flow in equal period t.
- r is the IRR for one selected period.
- n is the final period number.
The equation is usually solved numerically. This tool scans rates above -100% and across a wide positive range, identifies sign-changing roots, then refines each result. It displays the root closest to 10% when several valid roots exist and shows a warning instead of silently hiding the ambiguity.
For monthly or quarterly schedules, the direct solution is a rate per selected period. The calculator annualizes it using compound growth. For example, a 1% monthly IRR becomes about 12.68% annually, not 12%, because each month compounds.
Microsoft defines IRR for cash flows occurring at regular intervals and notes that at least one positive and one negative value are required. Its IRR function documentation also explains the iterative nature of the calculation.
Worked IRR Example
Assume a project requires ₹1,00,000 now and is expected to return ₹30,000, ₹35,000, ₹40,000 and ₹45,000 at the end of the next four years.
| Period | Cash flow | Meaning |
|---|---|---|
| 0 | -₹1,00,000 | Initial project cost |
| 1 | ₹30,000 | Year 1 net inflow |
| 2 | ₹35,000 | Year 2 net inflow |
| 3 | ₹40,000 | Year 3 net inflow |
| 4 | ₹45,000 | Year 4 net inflow |
The nominal net cash gain is ₹50,000, but that figure ignores timing. IRR discounts the later receipts until their present values exactly equal the ₹1,00,000 cost. At a 12% hurdle rate, NPV shows whether the project creates value above the required return. Load the example to see the complete comparison.
How to Read the Results
IRR and Hurdle-Rate Gap
Annualized IRR is the project's implied compound return. A positive gap means IRR exceeds your entered hurdle rate. A negative gap means the project falls short. This rule is useful only when the cash-flow pattern produces one economically meaningful IRR.
Net Present Value
NPV discounts every cash flow at your hurdle rate. A positive NPV means the project adds value under those assumptions. A negative NPV means discounted benefits do not cover discounted costs. NPV measures value in currency, so it captures project scale better than a percentage alone.
Modified Internal Rate of Return
MIRR separates the cost of financing negative cash flows from the rate earned when positive cash flows are reinvested. This avoids IRR's assumption that interim receipts compound at the IRR itself. The tool annualizes MIRR using the selected frequency.
Profitability Index
Profitability index divides the present value of positive cash flows by the present value of negative cash flows at the hurdle rate. A value above 1 indicates positive NPV. A value below 1 indicates negative NPV. PI is useful for ranking projects when available capital is limited, but project size still matters.
Simple and Discounted Payback
Simple payback estimates when cumulative undiscounted cash flow becomes non-negative. Discounted payback first discounts each flow at the hurdle rate. A project might achieve simple payback but never achieve discounted payback within the entered schedule.
IRR vs NPV, MIRR, XIRR, CAGR and ROI
| Metric | Best use | Main limitation |
|---|---|---|
| IRR | Equal-period project cash flows | Multiple roots and reinvestment assumption |
| NPV | Value added at a chosen hurdle rate | Requires a defensible discount rate |
| MIRR | Projects with realistic finance and reinvestment rates | Depends on two selected rate assumptions |
| XIRR | Cash flows on irregular dates | Can also produce multiple roots |
| CAGR | One beginning value and one ending value | Does not handle intermediate cash flows |
| ROI | Simple profit relative to cost | Usually ignores timing |
IRR and NPV answer different questions. IRR gives a percentage return. NPV gives the estimated currency value created at your required return. When two mutually exclusive projects differ in size or timing, NPV at a consistent hurdle rate usually gives the clearer value comparison.
Use the NPV Calculator for detailed discount-rate analysis. Use CAGR for one start and end value, and ROI for a simple profit-to-cost comparison.
Why an IRR Calculation Might Fail or Show Multiple Results
A conventional IRR needs at least one negative and one positive cash flow. All-positive or all-negative schedules never cross zero, so they do not have a standard IRR. A schedule might also have no root within the supported rate range.
Multiple IRRs arise when the cash-flow sign changes more than once. For example, a project might start with a cost, generate a large receipt, then require a major cleanup payment. Its NPV curve can cross zero more than once. Each crossing is mathematically valid, but none should be accepted without economic interpretation.
The root count tells you when this issue appears. Review NPV at realistic discount rates and use MIRR when interim reinvestment and financing assumptions need explicit treatment. Do not select the highest root because it looks attractive.
Cash-Flow Inputs That Improve an IRR Estimate
- Use net project cash flows, not accounting profit.
- Include the full initial cost, installation, setup and initial working capital.
- Add later maintenance, replacement and compliance costs as negative flows.
- Include taxes where you need an after-tax project return.
- Add working-capital recovery and net salvage value in the final period.
- Keep periods consistent. Do not mix monthly and annual rows.
- Use realistic operating volumes, prices, margins and terminal values.
- Run downside cases instead of relying on one optimistic forecast.
Inflation treatment must stay consistent. Use nominal cash flows with a nominal hurdle rate, or real cash flows with a real hurdle rate. Mixing the two distorts NPV and the acceptance signal.
IRR Limitations
IRR does not measure project size. A small project with a 30% IRR might add less total value than a larger project with a 17% IRR. Review NPV and capital constraints before ranking alternatives.
IRR assumes interim positive cash flows are reinvested at the IRR. This becomes aggressive when the calculated rate is high. MIRR replaces it with your entered reinvestment rate and often provides a more practical annual return estimate.
The result is only as reliable as the forecast. Delays, cost overruns, lower demand, taxes, financing terms and terminal-value errors change the outcome. IRR also says nothing about volatility, liquidity, legal risk or the probability of receiving projected cash flows.
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Frequently Asked Questions
What does IRR mean?
IRR means internal rate of return. It is the discount rate that makes the net present value of equal-period cash flows equal to zero.
What is a good IRR?
A good IRR exceeds a relevant hurdle rate after considering risk, tax, financing, inflation and alternative uses of capital. There is no universal target for every project.
What is the difference between IRR and XIRR?
IRR assumes equal time intervals between cash flows. XIRR uses exact calendar dates and is suitable for irregular investments, withdrawals or project payments.
Why does IRR require positive and negative cash flows?
The equation needs at least one cash outflow and one cash inflow to find a discount rate that balances their present values.
Can IRR be negative?
Yes. A negative IRR means the entered schedule produces a return below zero. Check cash-flow signs and assumptions before relying on the result.
Why can one project have multiple IRRs?
More than one cash-flow sign change can make the NPV curve cross zero several times. Each crossing produces a mathematical IRR, so NPV and MIRR should also be reviewed.
Should I choose a project when IRR exceeds the hurdle rate?
That is a common initial signal for a conventional cash-flow pattern. Confirm positive NPV, project scale, risk, funding limits and forecast quality before deciding.
What is MIRR?
Modified internal rate of return discounts negative cash flows at a finance rate and compounds positive cash flows at a reinvestment rate. It avoids IRR's reinvestment-at-IRR assumption.
Does IRR include inflation and tax?
IRR includes inflation and tax only when the entered cash flows include them. Match nominal cash flows with a nominal hurdle rate, or real cash flows with a real rate.
Financial disclaimer: This calculator provides educational estimates, not investment, tax, legal, accounting or financial advice. Results depend on complete cash flows, equal spacing and forecast assumptions. Verify major decisions with a qualified professional.