What the Internal Rate of Return Calculator is for
Find a unique periodic rate that sets NPV of equally spaced cash flows to zero.
It makes the prices, cash flows, rates, time periods, weights, and model conventions explicit so you can inspect an entered scenario without hidden live-market assumptions.
Calculation structure
Follow the stated model and units
Solve Σ[CF_t/(1+IRR)^t] = 0 for 1+IRR from 1e−14 through 11 (IRR through 1000%).
Visual explanation
See how the inputs become the result
Capital and cash flowstime and rate→entered modelScenario resultChanging one assumption changes the model—not the marketSolve Σ[CF_t/(1+IRR)^t] = 0 for 1+IRR from 1e−14 through 11 (IRR through 1000%).
Read the estimate correctly
Use the result within its boundaries
Cash flows −1,000 at time zero and 600 at years one and two have IRR about 13.066%.
Cash flows are equally spaced, not dated. Multiple supported roots are rejected, while numerically ambiguous shallow or closely spaced roots return an explicit reliability error.
Quick guide
How to use this calculator
Enter the cash flows, values, rates, timing, or portfolio assumptions named in the fields.
Use one consistent period and currency convention throughout the scenario.
Read the calculator-specific model limits before interpreting the result.
Calculation method
Calculation method
Solve Σ[CF_t/(1+IRR)^t] = 0 for 1+IRR from 1e−14 through 11 (IRR through 1000%).
Model, simulation, root, square-root, and compounding outputs are estimates and are visibly marked approximate.
Worked example
Worked example
Cash flows −1,000 at time zero and 600 at years one and two have IRR about 13.066%.
Solve Σ[CF_t/(1+IRR)^t] = 0 for 1+IRR from 1e−14 through 11 (IRR through 1000%).
Supported inputs
Precision and limits
Visible input limits
Inputs support up to 12 decimal places and lists support at most 1,200 rows. Iteration and simulation bounds are displayed in their fields.
International scope
No exchange, tax system, reporting standard, currency, fund rule, trading calendar, or market convention is selected automatically.
Decision boundary
Outputs are entered scenarios, not valuations, forecasts, risk limits, executable trades, suitability decisions, or recommendations.
Calculator-specific assumptions
Cash flows are equally spaced, not dated. Multiple supported roots are rejected, while numerically ambiguous shallow or closely spaced roots return an explicit reliability error.
