IRR Calculator - Internal Rate of Return Yield

Enter cash flows and timing dates

Begin by defining your cash flow timeline. Period 0 represents your initial capital outlay (which must be input as a negative value, representing an cash outflow). Add subsequent periods representing annual or monthly cash inflows (positive values). For dated projects (XIRR solver), supply the exact calendar date for each cash flow event to capture irregular spacing.

Select compounding and hurdle parameters

Define your corporate Hurdle Rate (e.g. WACC) to assess project feasibility. The tool will calculate the exact IRR and display it alongside the hurdle indicator. If you are comparing multiple scenarios, toggle the Base, Bull, and Bear modes to map varying operational cash projections.

Scenario cash flows inputs

Capital budgeting relies on sensitivity bounds. In the left panel, you can independently configure the cash flows for Bull (upside), Base (expected), and Bear (downside) parameters. The inputs are isolated in separate scenario scopes to prevent data cross-contamination during active modeling.

Intrinsic IRR yield outputs comparison

The Scenario Comparison Card maps the calculated IRR of each profile side-by-side. Inspecting the differences in internal yields relative to the hurdle rate highlights whether downside events (Bear) will drop the project below its required capital cost threshold.

Hurdle rate vs NPV table

Since the IRR is the discount rate that forces Net Present Value to zero (NPV = 0), the calculator plots a discount rate sensitivity matrix. It calculates the resulting NPV at discount steps ranging from -4.00% to +4.00% around the base hurdle rate, mapping out the project's NPV Profile Curve.

Newton-Raphson vs bisection solver modes

The underlying calculation engine uses numeric approximation to solve for the root. The Newton-Raphson solver converges rapidly but can fail if cash flows fluctuate frequently, causing derivative slopes to cycle. Under such conditions, the engine falls back to a Bisection solver to guarantee mathematical safety.

Example cash flow assumptions

To demonstrate the IRR calculation, let's look at a simple capital project with a 3-year timeline:

• Initial Outlay (Year 0) = -$100,000 (Cash Outflow)
• Year 1 Cash Inflow = $30,000
• Year 2 Cash Inflow = $40,000
• Year 3 Cash Inflow = $50,000

Step-by-step yield solving

We solve for the rate (r) that satisfies: NPV = -$100,000 + $30,000/(1+r)^1 + $40,000/(1+r)^2 + $50,000/(1+r)^3 = 0.

By testing trial rates, if we choose r = 10%, NPV is +$9,635. If we choose r = 15%, NPV is -$1,102.

Through numerical interpolation, the exact rate that drives the NPV to exactly zero is solved at 14.42%. This 14.42% is the project's Internal Rate of Return (IRR).

Yield vs hurdle rate thresholds

If the solved IRR is strictly greater than the Corporate Hurdle Rate (e.g., WACC), the project is economically viable as it generates returns exceeding its funding costs. If the IRR is below the hurdle rate, the investment destroys value on a present-value basis and should be rejected.

Reinvestment rate assumption limits

A major caveat of IRR is the reinvestment rate assumption. The formula implicitly assumes all positive cash inflows are immediately reinvested at the calculated IRR yield. For highly profitable projects with IRRs of 40%+, this assumption is often unrealistic. NPV or Modified IRR (MIRR) should be used as secondary checks.