IRR Calculator

May 4, 2026

Internal Rate of Return (IRR) is a core metric for evaluating the profitability of an investment or project. Instead of building a complex spreadsheet, you can use the free IRR calculator above to instantly find the rate at which your net present value equals zero.

What is Internal Rate of Return (IRR)?

IRR is the discount rate that makes the net present value (NPV) of all cash flows from an investment equal to zero. In simpler terms, it represents the expected average annual return–adjusted for the time value of money–that a project will generate over its life.

When an IRR exceeds the cost of capital or a predetermined hurdle rate, the investment is generally considered worth pursuing. If it falls below that threshold, the project may destroy value.

IRR Formula and Calculation

The mathematical foundation sets NPV to zero:

NPV = Σ [CFₜ / (1 + IRR)ᵗ] – Initial Investment = 0

Where CFₜ is the net cash inflow during period t. Because the equation is non‑linear, IRR is computed iteratively (trial and error) in practice. The calculator above automates that process: enter your upfront investment as a negative number and each subsequent expected net inflow. Results appear in seconds.

For a quick manual verification, you can use linear interpolation between two discount rates that produce a small positive and a small negative NPV.

How to Interpret IRR Results

Compare the calculated IRR against your hurdle rate or cost of capital. If the IRR is higher, the investment adds value. For example, a project with an IRR of 18% easily clears a 10% required return, signaling a strong opportunity.

When screening multiple independent projects, those with the highest IRRs above the hurdle are the most attractive–provided they carry similar risk. For mutually exclusive projects, also check NPV to avoid scale mismatches.

IRR vs. NPV: Which is Better?

IRR gives a percentage, making it intuitive for comparing against financing rates. NPV provides the absolute dollar value added, which is more reliable when choosing between projects of different sizes or horizons. A very small project might have a stellar IRR but contribute little total value; a larger project with a lower IRR might boost wealth more. For final capital‑budgeting decisions, NPV is usually the preferred measure.

Advantages and Disadvantages of Using IRR

Advantages

Incorporates the time value of money.
Expresses profitability as a single, easy‑to‑communicate rate.
Directly comparable with a firm’s cost of capital.

Disadvantages

Assumes interim cash flows can be reinvested at the IRR itself (often unrealistic).
Can produce multiple IRRs when cash flows change direction more than once.
Ignores project scale; a high IRR does not guarantee the highest total return.

Example of IRR Calculation

Assume you invest $5,000 today and receive $2,000 each year for the next three years. The cash flow stream is: –$5,000, $2,000, $2,000, $2,000.

Let’s find the IRR using two discount rates:

At 9%, NPV ≈ $62.73
At 10%, NPV ≈ –$26.30

Using linear interpolation:

IRR ≈ 9% + [62.73 / (62.73 + 26.30)] × 1% ≈ 9.70%

A more precise calculation (or the IRR calculator) yields 9.70%. If your required return is 8%, the project is acceptable.

The information provided is for educational purposes only and does not constitute financial advice. Consult a qualified professional before making investment decisions.

Frequently Asked Questions

What is a good IRR for an investment?

A “good” IRR depends on the investor’s required rate of return and the risk level. Generally, an IRR above the cost of capital or a benchmark return (e.g., 7–10% for low-risk projects, 15–25% for higher risk) is considered acceptable.

How does IRR differ from ROI?

ROI shows total return as a percentage of initial investment over a specific period, while IRR accounts for the time value of money and the exact timing of cash flows. IRR is better for comparing projects with different cash flow schedules.

Can IRR be negative and what does it mean?

Yes, negative IRR indicates that the investment loses money, meaning the present value of cash outflows exceeds inflows. It suggests the project is not profitable and should be rejected if a positive return is required.

What are the main limitations of IRR?

IRR assumes reinvestment at the same rate, which may be unrealistic. It can produce multiple values for non-conventional cash flows and may favor short-term projects with high early returns. Modified IRR (MIRR) addresses some of these issues.

How do I calculate IRR in Excel?

Use the IRR() function: =IRR(range of cash flows, guess). The range should include the initial investment (negative) and all future net cash flows. Provide an optional guess rate to help the iteration process converge.

Is a higher IRR always better?

Not necessarily. A higher IRR may come with higher risk, and for mutually exclusive projects, the project with a lower IRR might add more total value if it is much larger in scale. NPV should also be considered.