How to use the IRR calculator
- One cash flow per line; period 0 is today—outflows negative, inflows positive.
- Optional hurdle rate shows NPV at that rate beside IRR.
- Check the parsed flow table on the right; commas or semicolons work.
- Presets, add period, copy link to save flows.
What IRR means
The discount rate that sets NPV to zero—shown as an annual percent. Reinvestment at IRR is a classic assumption; pair with NPV on large decisions.
Pair with NPV
Open the NPV calculator with the same flows at your hurdle rate. If IRR does not converge, NPV at a fixed rate still helps.
When IRR fails
Need both signs and at least two periods. Check typos and period spacing (keep periods equal length).
Frequently asked questions
What is IRR?
Internal rate of return is the discount rate that makes the net present value of your cash flows zero—shown here as an annual percentage. Used to compare projects against hurdle rates.
How do I enter cash flows?
One value per line, period 0 = today: outflows negative, inflows positive. Need at least two periods and both signs for a solution.
What if IRR does not calculate?
You may lack both signs or have no root in range. Check signs, merge periods, or use NPV at your discount rate instead.
How do IRR and NPV work together?
IRR is the implied return; NPV uses your stated discount rate. Open the NPV calculator with the same flows from the results link.
What is the reinvestment assumption?
Classic IRR assumes interim flows reinvest at the IRR itself—which may not hold. Pair with NPV on large decisions.
Must periods be years?
Each line is one period—keep spacing consistent (e.g., all annual or all monthly) when interpreting the rate.
Comparing multiple projects?
Run each scenario separately and compare IRR and NPV at the same discount rate; use share below to save inputs when needed.
Can I share this scenario with someone?
Yes. Copy link below the form keeps your current inputs so you can share the scenario or save it for later.