Quick Answer: Calculate the internal rate of return for a series of uneven cash flows and compare it with net present value at a chosen discount rate.
How This Calculator Works
IRR is the discount rate that makes the net present value of all investment cash flows equal zero. It is commonly used to compare projects, private investments, real estate deals, and business acquisitions with uneven cash flow timing.
Worked Scenario: Scenario: Evaluating a Multi-Year Project
A business invests 10,000 upfront and expects annual cash inflows of 3,000, 4,200, and 6,800 over the next three years.
Scenario Inputs
- Initial outflow: $10,000
- Future cash inflows: 3,000, 4,200, $6,800
- Decision metric: IRR and NPV
Outcome: The IRR shows the annualized break-even discount rate for the projected cash flows. If IRR is higher than the required return, the project may be financially attractive before adjusting for risk.
Formula and Methodology
NPV = CF0 + CF1 / (1 + r)^1 + CF2 / (1 + r)^2 + ... + CFn / (1 + r)^n
IRR is the rate r where NPV = 0
Profitability index = Total positive cash flows / Absolute total negative cash flows
Variables
- CF0: The initial investment or first-period cash flow, usually negative
- CFn: Cash flow in period n
- r: The discount rate or internal rate of return
Assumptions
- Cash flows are treated as end-of-year annual amounts after the initial investment.
- Positive values are inflows and negative values are additional outflows.
- IRR is found numerically by solving for the discount rate where NPV equals zero.
Limitations
- Cash flow patterns with multiple sign changes can have multiple IRRs; this calculator reports the first root found in the supported range.
- IRR assumes interim cash flows can be reinvested at the IRR, which may not match reality.
- IRR should be compared with NPV, project scale, risk, and capital constraints before making a decision.
Practical FAQs
What is internal rate of return?
IRR is the discount rate that makes the present value of future cash flows equal the initial investment. In other words, it is the break-even annual return implied by the cash flow schedule.
How should I enter cash outflows?
Enter additional investments, costs, or losses as negative cash flows. Enter distributions, sale proceeds, or income as positive cash flows.
Is a higher IRR always better?
Not always. A small project can have a high IRR but low total value. Compare IRR with NPV, investment size, timing, and risk.