How to use this calculator
- Enter annual cash flows including time zero.
- Choose a display currency, then select Calculate. Results also update after a brief pause while you edit.
- Read the result with the assumptions below. Export details or save a second scenario to compare your choices.
Formula and method
Assumptions and limitations
Nonconventional sign changes can create multiple or no IRRs and are explicitly rejected rather than selecting a misleading root. Up to 100 equally spaced annual cash flows; irregular dates require XIRR.
Worked example
An outflow of 1,000 today followed by zero after one year and 1,210 after two years has annual IRR of 10%.
What the result means
Solve a unique IRR for a conventional investment: an initial outflow followed by nonnegative annual inflows.
Common questions
How is the calculation performed?
Find the annual rate r greater than −100% that makes sum(CF_t / (1 + r)^t) = 0, using a bracketed solver.
What does the model leave out?
Nonconventional sign changes can create multiple or no IRRs and are explicitly rejected rather than selecting a misleading root. Up to 100 equally spaced annual cash flows; irregular dates require XIRR.
Methodology and transparency
Calculation specification reviewed on 2026-10-14. Mathematical implementation is tested against independent reference fixtures. This does not imply review by a licensed financial professional. Read the testing and precision policy.
Background reference: openstax.org — financial method. FinanceMath implements its own calculator.