# IRR Calculator: Annualized Return From Uneven Cash Flows URL: https://aistartupinsights.com/tools/irr-calculator Type: tool Locale: en Published: 2026-11-03 Updated: 2026-11-04 --- > Enter what you invested and what came back each period. The calculator solves for the internal rate of return, annualizes it and shows the multiple. *Free finance tool* ## IRR Calculator for Uneven Investment Cash Flows Enter what you invested and what came back each period. Get the internal rate of return, the annualized rate and the multiple, live. ## Calculate your internal rate of return Prefilled with a worked example: 2,000,000 invested, 10,000,000 returned in period 5. Change any number and the result updates. *[Interactive widget — see the live page for the full experience]* ## What goes into the IRR number ### The equation it solves IRR is the rate r that makes the sum of CF(t) / (1 + r)^t equal zero, with the amount invested counted as a negative flow at period 0. Nothing else is assumed: no fees, no taxes, no reinvestment schedule. ### How the rate is found There is no closed form for most schedules. The page scans candidate rates for the point where the net present value flips sign, then bisects that bracket 200 times, which pins the rate far below a hundredth of a percent. ### Per period versus annualized With quarterly or monthly flows, the per-period rate is compounded to a yearly figure as (1 + r)^n - 1, where n is 4 or 12. A 10% quarterly IRR is a 46.41% annualized IRR, not 40%. *Worked examples* ## Same multiple, very different IRR The time axis is what separates IRR from a plain multiple. These figures come straight from the formula above, so you can reproduce each one in the calculator. - 2M invested, 10M back in year 5 (5.0x): 37.97% IRR - 3.0x returned in year 5: 24.57% IRR - 3.0x returned in year 3: 44.22% IRR - 10.0x returned in year 10: 25.89% IRR ## Run an IRR check in four steps 1. **Set the amount invested** — Type the capital you put in at period 0 as a positive number. The calculator treats it as an outflow. 2. **Choose the period length** — Pick years, quarters or months so the flows are evenly spaced. Equal spacing is a requirement of the standard IRR. 3. **Fill in cash flows** — Enter distributions, exits or dividends as positive numbers in the period they arrive. Enter follow-on investments as negative numbers. 4. **Read three numbers together** — Look at the IRR, the annualized rate and the multiple on invested capital. A high IRR with a low multiple means a fast but small win. ## IRR calculator questions ### What does the IRR calculator compute? It finds the single discount rate at which the net present value of your cash flows equals zero. That rate is the internal rate of return, shown per period and annualized for quarterly or monthly schedules. ### Is the IRR calculator free, and is my data stored? It is free and needs no signup. The calculation runs in your browser, so the amounts you type are not sent to a server. Only an anonymous tool-run counter is recorded. ### Which formula does it use? It solves the sum of CF(t) / (1 + r)^t = 0 for r, where CF(0) is the amount invested as a negative number. It scans rates from -99% upward for a sign change, then narrows the bracket by bisection until the value is stable. ### How is this different from Excel IRR and XIRR? Excel IRR assumes equally spaced periods, which is what this page does. XIRR uses actual calendar dates, so it fits irregular dates. If your flows land on exact dates, use XIRR; for annual, quarterly or monthly schedules, the results match. ### Why does it say no IRR exists? IRR needs at least one outflow and one inflow. If every flow has the same sign, no rate can bring the net present value to zero. Check that the invested amount is positive here and that returns are entered as positive numbers. ### What happens with several follow-on rounds or reinvestments? A schedule that flips sign more than once can have more than one valid IRR. The calculator returns the lowest rate that solves the equation and warns you when the schedule has multiple sign changes. ### How do I read the multiple on invested capital? It divides total cash returned by total cash invested, including negative follow-on flows. A 5x multiple over 10 years and a 5x multiple over 3 years look identical there, while IRR separates them. ### Does IRR assume I can reinvest at the same rate? IRR implicitly treats interim cash as reinvested at the IRR itself, which can overstate results for very high rates. For a conservative check, compare against the multiple on invested capital. ## Track AI startup returns with structured data AI Startup Insights ingests funding rounds, hiring and pricing moves every four hours and turns them into briefings you can act on. *Call to action: Read the latest briefings* ## FAQ ### What does the IRR calculator compute? It finds the single discount rate at which the net present value of your cash flows equals zero. That rate is the internal rate of return, shown per period and annualized for quarterly or monthly schedules. ### Is the IRR calculator free, and is my data stored? It is free and needs no signup. The calculation runs in your browser, so the amounts you type are not sent to a server. Only an anonymous tool-run counter is recorded. ### Which formula does it use? It solves the sum of CF(t) / (1 + r)^t = 0 for r, where CF(0) is the amount invested as a negative number. It scans rates from -99% upward for a sign change, then narrows the bracket by bisection until the value is stable. ### How is this different from Excel IRR and XIRR? Excel IRR assumes equally spaced periods, which is what this page does. XIRR uses actual calendar dates, so it fits irregular dates. If your flows land on exact dates, use XIRR; for annual, quarterly or monthly schedules, the results match. ### Why does it say no IRR exists? IRR needs at least one outflow and one inflow. If every flow has the same sign, no rate can bring the net present value to zero. Check that the invested amount is positive here and that returns are entered as positive numbers. ### What happens with several follow-on rounds or reinvestments? A schedule that flips sign more than once can have more than one valid IRR. The calculator returns the lowest rate that solves the equation and warns you when the schedule has multiple sign changes. ### How do I read the multiple on invested capital? It divides total cash returned by total cash invested, including negative follow-on flows. A 5x multiple over 10 years and a 5x multiple over 3 years look identical there, while IRR separates them. ### Does IRR assume I can reinvest at the same rate? IRR implicitly treats interim cash as reinvested at the IRR itself, which can overstate results for very high rates. For a conservative check, compare against the multiple on invested capital.