Every project proposal is a choice between investing time and money now and receiving returns later. As a future project leader, you need to know which options will add value. Internal rate of return (IRR) is one tool that helps you make that call.
In today’s blog post, I will explain what IRR is, how to calculate it, why it matters for the PMP exam, and how recent market data show that returns vary widely across industries. Along the way, you’ll see examples, a handy table, and answers to common questions.
Let us get started.
What is the Internal Rate of Return (IRR)?
At its core, the internal rate of return is the discount rate at which the present value of a project’s inflows equals its outflows. In other words, IRR is the growth rate that sets net present value equal to zero. It shows how fast your investment grows each year when cash flows are included. A higher IRR indicates quicker compounding.
IRR is “internal” because it excludes external factors such as inflation, market conditions, and corporate discount rates. This allows apples-to-apples comparisons across projects. While return on investment (ROI) measures the total gain over the project’s life, IRR focuses on the annualized rate of return.
IRR Vs NPV and ROI
IRR does not exist in isolation. When you perform capital budgeting, you often compare three metrics: IRR, net present value (NPV), and ROI. IRR gives you a percentage rate. NPV provides a dollar amount that tells you how much value the project adds. ROI divides total gains by the investment cost and shows overall profitability. Because each measure conveys different information, companies use them together.
Below is a table summarizing the main differences:
| Metric | What it measures | Strength | Limitation |
| IRR | Discount rate that sets NPV to zero | Easy to compare against the cost of capital; indicates annual growth | Can be difficult to calculate manually; assumes reinvestment at the same rate |
| NPV | Present value of cash inflows minus outflows | Shows value created in dollars; helps decide if a project adds wealth | Sensitive to the choice of discount rate; does not express the rate of return |
| ROI | Total return divided by initial investment | Simple to understand; good for quick comparisons | Ignores the timing of cash flows and the time value of money |
By combining these metrics, you can see both the growth rate and the absolute value created.
How to Calculate IRR
The most common formula for IRR sets NPV equal to zero and solves for the discount rate:
0 = CF0 + CF1/(1+IRR)¹ + CF2/(1+IRR)² + … + CFn/(1+IRR)^n
Here, CF0 is the initial investment (a negative number), and CF1 through CFn are future cash flows. Because the equation is nonlinear, you solve it through trial-and-error or by using software.
For a single future value, there’s a shortcut:
IRR = (FV / PV)^(1/n) – 1
where FV is the future value, PV is the present value, and n is the number of periods.
Example IRR Calculation
Imagine you are assessing a small automation project. It requires an investment of $80,000 today and is expected to produce cash inflows of $35,000 in year 1, $40,000 in year 2, and $30,000 in year 3. Your company’s required rate of return is 10%. The goal is to see whether the project’s IRR exceeds 10%.
1. Set up the equation:
0 = 80,000 + 35,000/(1+IRR) + 40,000/(1+IRR)² + 30,000/(1+IRR)³
2. Try Different Rates: If you guess 12% you get a positive NPV. At 14%, NPV is still positive but smaller. At 15% NPV turns slightly negative. The exact IRR is approximately 14.5%, which is higher than the required 10%. That means the project should be accepted.
3. Use Software: In Excel, you can type the cash flows into cells A1 to A4 (80,000, 35,000, 40,000, 30,000) and use =IRR(A1:A4) to get 14.5%.
This simple example shows how IRR indicates whether a project beats the company’s required return. Remember that the IRR function in Excel automates the trial-and-error step.
What Is a Good IRR?
There is no universal “good” IRR. What counts as good depends on the cost of capital and the industry. A positive IRR means the project or investment is expected to return value. A negative IRR can happen when cash flows alternate between positive and negative, making the metric less useful.
To evaluate the quality of an IRR, you must compare it with the company’s required rate of return (also known as the hurdle rate). If the IRR exceeds the hurdle rate, the project may add value; if it falls short, it should be rejected. Real-world data show how returns fluctuate:
| Sector/Asset | 2024 Return (approx.) | Insight | Source |
| Closed-end real estate funds | 1.1% pooled IRR through Q3 2024 | Many funds recorded negative returns as higher interest rates hit property values. | McKinsey Global Private Markets Report 2025 |
| Open-end real estate funds | 1.6% gross return in 2024 | Returns remained under pressure, marking the second annual decline since 2008. | McKinsey Global Private Markets Report 2025 |
| Manufactured housing | 11.7% total return in 2024 | This niche real estate segment delivered substantial gains. | McKinsey Global Private Markets Report 2025 |
| Senior housing | 5.6% total return in 2024 | Aging populations supported moderate returns. | McKinsey Global Private Markets Report 2025 |
| Data centers | 11.2% total return in 2024 | Demand for cloud services drove high returns. | McKinsey Global Private Markets Report 2025 |
These figures demonstrate that IRR and related returns can be either positive or negative, depending on market conditions. They also highlight why comparing an IRR with industry benchmarks matters. For example, an IRR of 8% might be attractive in a low-return environment but unacceptable for an infrastructure project requiring heavy capital.
Pros and Cons of IRR
Advantages:
- Easy to compare projects: IRR condenses a series of cash flows into a single percentage, allowing managers to compare potential projects against the hurdle rate.
- Considers the time value of money: Like NPV, IRR discounts future cash flows, giving earlier returns more weight.
- Encourages strategic thinking: Because stakeholders often speak in terms of rates of return, presenting an IRR can help secure buy-in for a project.
Disadvantages:
- Complex calculations: Solving the IRR equation requires iterative methods or software. Manual calculation is slow and error-prone.
- Reinvestment assumption: IRR assumes that interim cash flows can be reinvested at the same rate, which is rarely realistic. This can overstate returns.
- Ignores project size: A small project might have a high IRR but contribute little in dollar terms. Always consider NPV and overall cash flow.
A careful analyst weighs these pros and cons and uses IRR alongside other metrics rather than relying on it alone.
IRR and the PMP Exam
Why does the PMP exam care about IRR? Project managers make decisions that affect an organization’s financial health. The exam expects you to understand how IRR compares with NPV and the payback period. You rarely need to compute an IRR by hand. Instead, questions ask you to interpret a given value and choose the project with the highest IRR. A high IRR signals a desirable project; a low or negative IRR suggests you should look elsewhere. Also, remember that IRR is just one tool – use it with other metrics like NPV and ROI.
When reviewing exam questions, pay attention to the company’s required rate of return. If a project’s IRR exceeds that threshold, it is usually the correct choice. Keep in mind the time value of money and ensure you understand which metric is being compared.
FAQs
Q1. Why is IRR called “internal”?
It focuses only on the project’s cash flows and ignores external factors such as inflation and overall market conditions.
Q2. Can IRR be negative?
Yes. An investment with alternating positive and negative cash flows may produce a negative IRR. Negative values indicate the project fails to recover its initial cost.
Q3. Is a higher IRR always better?
Not always. You must compare IRR with the company’s hurdle rate and industry benchmarks. A high IRR on a tiny project may add less value than a moderate IRR on a larger project.
Q4. How does IRR relate to NPV?
IRR is the discount rate at which NPV equals zero. Both metrics account for the time value of money and should be used together in decision-making.
Q5. Do I need to memorize the formula for the PMP exam?
You should know the concept and be familiar with the standard formula, but exam questions typically provide values and ask you to interpret them rather than solve the equation.
Summary
Understanding the internal rate of return helps you make smarter project decisions and prepares you for the PMP exam. IRR tells you the annual growth rate of an investment by finding the discount rate that sets NPV to zero. When used with NPV and ROI, it provides a fuller picture of a project’s value. Remember that a “good” IRR depends on the cost of capital and industry conditions. Recent data show that real estate funds posted negative pooled IRRs in 2024 while data centers and manufactured housing delivered double-digit returns, highlighting the importance of context.
Further Reading:
I am Mohammad Fahad Usmani, B.E. PMP, PMI-RMP. I have been blogging on project management topics since 2011. To date, thousands of professionals have passed the PMP exam using my resources.
