IRR Calculator
Find the internal rate of return of any cash flow series.
All calculations happen locally in your browser — nothing is uploaded, stored or tracked.
Enter your cash flows
Initial investment negative, then each period's flow.
Set a discount rate
For the NPV comparison.
Read the IRR
Plus NPV at your chosen rate.
What Is IRR?
The Internal Rate of Return is the discount rate that makes the net present value of a series of cash flows zero — the average annual return your investment delivers, accounting for the timing of every cash flow.
Enter the initial investment as a negative cash flow and each period's net cash flow after it. The calculator finds IRR by numerical search (bisection) and also reports the NPV at a discount rate you choose.
The Definition
The IRR is the rate r solving that equation. For non-conventional cash flows with multiple sign changes, multiple IRRs can exist — the calculator reports the rate closest to zero as the standard convention.
Your data never leaves your device.
Every calculation on this site runs in your browser using vanilla JavaScript. Nothing is uploaded, stored or tracked.
- 100% local, client-side calculations
- No data stored on any server
- No tracking, no analytics, no ads scripts
- Works offline once loaded
Frequently Asked Questions
How is IRR calculated?
By finding the discount rate at which the present value of all cash flows sums to zero — the calculator solves it numerically.
What is a good IRR?
Compare it with your required return or cost of capital. If IRR exceeds the hurdle rate, the project is attractive on this measure.
What is the difference between IRR and ROI?
IRR accounts for the timing of cash flows; ROI does not. IRR is the more informative measure for investments with multiple cash flows.
Why does my IRR look wrong with non-standard cash flows?
Multiple sign changes can produce multiple IRRs — a known limitation of the metric.
What if the cash flows never turn positive?
There is no valid IRR — the calculator reports an error.