IRR Calculator

The IRR calculator analyzes a cash-flow series to determine the discount rate that sets the net present value to zero. It supports a starting investment (negative CF0) and subsequent period cash flows (positive or negative). The core logic is agnostic to industry and accommodates standard finance conventions. Conceptually, IRR is the rate that makes the sum of discounted cash flows equal to the initial outlay, reflecting the project’s expected annual return. The tool exposes robust numerical methods (default Newton-Raphson with a bisection fallback) to converge on the IRR even with non-conventional cash flows. Use cases include comparing competing projects, validating hurdle-rate targets, and performing sensitivity checks across different cash-flow scenarios. The system can handle both fixed and optional irregular timing if the user provides period dates. It provides diagnostic signals when multiple IRRs exist or when convergence fails, guiding analysts toward alternative assumptions. Unique value lies in eliminating manual spreadsheet errors, enabling rapid scenario analysis, and supporting non-standard timing with clear convergence diagnostics.