Calculate internal rate of return (IRR) for capital projects, real estate, and private equity investments. Build a cash flow timeline, compute IRR, and review net present value (NPV) at a 10% discount rate.
Use negative values for investments/outflows and positive for returns/inflows.
Enter initial investment as a negative number and add projected cash inflows for each year. Click "Calculate IRR" to see internal rate of return and NPV metrics.
The Internal Rate of Return (IRR) is one of the most widely used metrics in capital budgeting and investment analysis. It represents the annualized effective compounded return rate that can be earned on an invested capital — in other words, the discount rate at which the Net Present Value (NPV) of all future cash flows from a project equals zero.
IRR is deeply connected to NPV. NPV measures the absolute dollar value that an investment creates after discounting all future cash flows back to today at a chosen rate. When you raise that discount rate high enough, NPV eventually reaches zero. That exact rate is the IRR. A project with a positive NPV at a given hurdle rate will always have an IRR greater than that hurdle rate — and vice versa.
Mathematically, the IRR (denoted r) is the value that satisfies:
Where is the cash flow at period , is the total number of periods, and is the unknown rate we solve for. Because this is a polynomial equation of degree , there is no closed-form algebraic solution for, so numerical methods like bisection or Newton-Raphson iteration are used — exactly as this calculator does.
The most important use of IRR is comparing it to a hurdle rate — the minimum acceptable rate of return set by an organization, also often called the required rate of return or Weighted Average Cost of Capital (WACC).
For example, if a real estate investment has an IRR of 14% and your required return (WACC) is 9%, the spread of 5% represents excess return — a strong signal to proceed. Private equity funds typically target IRRs of 20% or higher to compensate for illiquidity and risk.
These three metrics answer different questions and work best when used together:
| Metric | Output | Best For |
|---|---|---|
| IRR | Percentage return rate | Comparing projects of similar size/duration |
| MIRR | Modified % return rate | Projects with non-conventional cash flows or different reinvestment assumptions |
| NPV | Absolute dollar value | Mutually exclusive projects, maximizing total firm value |
When two projects have conflicting IRR and NPV rankings — which happens when they differ significantly in scale or timing — always defer to NPV for decision-making, as it directly measures value creation in dollar terms.
Despite its popularity, IRR has well-documented limitations that every analyst should understand:
IRR is used across a wide range of finance and investment contexts:
Learn more about IRR and investment analysis from authoritative sources:
Financial Disclaimer
This IRR calculator is provided for educational and informational purposes only. Results are based solely on the cash flow inputs you provide and mathematical computation. This tool does not constitute financial, investment, tax, or legal advice. IRR is one of many metrics used in investment analysis and should not be used in isolation. Always consult a qualified financial professional before making investment decisions. Past performance and projected returns are not guarantees of future results.
Sit in a real estate pitch. Private equity deck. Any investment meeting. Someone will say the IRR is 22%, or 18%, or 31%. Everyone writes it down.
Ask five of those people afterward what IRR actually measures. You'll get five different answers — and at least two of them will be confidently wrong.
IRR is the most cited metric in finance and one of the least understood. Including by the people citing it.
IRR is the discount rate that makes the Net Present Value of all your cash flows equal zero.
That definition is useless until you understand NPV. So: money today is worth more than money later. If you can earn 8% elsewhere, then $1 arriving one year from now is only worth \\frac{\\$1}{1.08} \\approx \\$0.926 in today's terms. NPV applies that logic to every cash flow across the entire investment.
NPV Formula
where = cash flow at time t, = discount rate
IRR asks: what value of r makes NPV = 0? That rate is your internal rate of return. It's the breakeven discount rate — the return the investment is implicitly earning.
You invest $200,000 today. The deal pays you $12,000/year for 4 years, then $252,000 in year 5 (cash flow + principal returned).
| Year | Cash Flow | PV at 13.1% |
|---|---|---|
| 0 | −$200,000 | −$200,000 |
| 1 | $12,000 | $10,609 |
| 2 | $12,000 | $9,380 |
| 3 | $12,000 | $8,293 |
| 4 | $12,000 | $7,332 |
| 5 | $252,000 | $136,386 (approx) |
At a discount rate of ~13.1%, the present values sum to roughly $200,000 — NPV ≈ 0. So IRR = 13.1%.
You can't solve this algebraically. There's no formula that spits out the answer. Every calculator and spreadsheet solves it by iteration — guessing and refining until NPV gets close enough to zero.
IRR has a few genuine blind spots. Not hypothetical edge cases — things that come up in real deals.
A 40% IRR on a $10,000 investment makes you $4,000. A 15% IRR on a $10,000,000 investment makes you $1,500,000. IRR says the first deal is better. Your bank account disagrees.
This is why serious investors look at both IRR (efficiency) and NPV (dollars). IRR ranks deals. NPV measures wealth created.
If your cash flows change sign more than once — you invest, get some back, invest more, then get paid out — the math can produce two valid IRR solutions. Most spreadsheets just show you one. Which one depends on the starting guess.
Real example: a mining project that requires a large cleanup cost at the end. Cash flows go negative → positive → negative. Can produce two valid IRRs. Neither one is "the" answer.
IRR implicitly assumes that every cash flow you receive gets reinvested at the IRR itself. A deal with 25% IRR assumes you can redeploy those interim distributions at 25% too. Usually unrealistic.
MIRR (Modified IRR) fixes this by letting you specify a separate reinvestment rate. Less commonly used, but more honest.
| Metric | What it measures | What it misses |
|---|---|---|
| IRR | Annualized return rate, time-weighted | Deal size, reinvestment rate |
| NPV | Total dollars created above your hurdle rate | Return efficiency (a huge NPV could come from a mediocre rate on a giant deal) |
| ROI | Total return as % of cost | Time — 5% ROI over 1 year is completely different from 5% over 10 years |
| Cash-on-Cash | Annual cash income ÷ cash invested | Appreciation, loan paydown — anything that isn't cash in hand |
Smart investors use all four. IRR for ranking. NPV for sizing the prize. Cash-on-cash for "does this thing pay my bills while I hold it." ROI for back-of-napkin comparisons.
Depends entirely on the asset class and risk. Real estate private equity typically targets 15–25%. Venture capital expects 25%+ because most deals fail. S&P 500 historically returns ~10% annualized. A "good" IRR is one that exceeds your hurdle rate — the minimum return that justifies the risk and illiquidity of not putting money in the index fund instead.
The IRR equation is a polynomial. For a 5-year investment, it's a 5th-degree polynomial. The Abel-Ruffini theorem proves there's no general algebraic solution for polynomials of degree 5 or higher. So every tool — Excel, calculators, Python — uses numerical methods (Newton-Raphson iteration) to converge on an answer.
CAGR works for a single investment with one entry and one exit — no intermediate cash flows. IRR handles multiple cash flows at different times. For a buy-and-hold with no dividends, they give the same answer. For anything with distributions along the way, use IRR.
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