How to use this calculator
Enter signed flows beginning with period 0. The calculator reports a unique IRR only if exactly one valid real solution exists.
Formula and method
IRR solves Σₜ Cₜ/(1+r)ᵗ = 0 for r > −100%. The numerical search isolates positive roots of the equivalent polynomial in x = 1/(1+r).
Worked example
−1,000 now, then 600 at each of periods 1 and 2, has one IRR of about 13.0662% per period. −100, 230, −132 has two IRRs: 10% and 20%.
Assumptions and supported scope
Equal periods; no irregular-date XIRR. Zero or multiple roots are reported explicitly. Very uneven cash-flow magnitudes may exceed the reliable numerical search and are rejected.
Method references
Method and worked example checked against the calculator implementation. About our methods · Report a correction