IRR Calculator 🔒 Your data never leaves your browser.
Calculate internal rate of return from a series of cash flows.
One per line, or separated by commas/spaces. The first value is year 0 (usually the negative initial investment).
About this tool
This IRR calculator (internal rate of return) finds the single discount rate at which a series of cash flows has a net present value of exactly zero. Put another way, it is the annualized return rate the investment actually delivers, given the amount you put in and the amounts you get back over time. Enter year 0 (typically the negative initial investment) followed by the cash flow expected in each later year, and the tool solves for that rate. The rule of thumb: a project is generally worth pursuing when its IRR exceeds your required rate of return (your hurdle rate) — if IRR is below that bar, the same money is likely better deployed elsewhere.
With the default example — an outlay of -1000 followed by 500, 400, 300 and 100 — the IRR comes out to a little over 15%. If your hurdle rate is 10%, this project clears it comfortably; if it’s 20%, it falls short. Because IRR and NPV are two views of the same cash-flow model, this tool is the natural companion to the NPV calculator — use NPV when you already know your discount rate and want a dollar figure, and use IRR when you want the break-even rate itself. Everything runs locally in your browser as you type — nothing is uploaded — so treat the result as a planning estimate rather than formal investment advice.
Frequently asked questions
Can a series of cash flows have more than one IRR?
Yes — if the cash flows change sign more than once (e.g. negative, then positive, then negative again, like an investment with a large cleanup cost at the end), there can mathematically be multiple discount rates where NPV crosses zero. This calculator finds one root within a wide search range using bisection; for typical "invest once up front, then receive returns" patterns (only one sign change) there's exactly one IRR and this isn't a concern, but for unusual cash-flow shapes with multiple sign changes, treat a single IRR result with some caution and consider looking at the full NPV profile instead.