IRR calculator
Find the internal rate of return of evenly spaced cash flows, including multiple-rate cases.
A clear answer. Here’s how.
Finds every discount rate r where the sum of flow ÷ (1 + r)^period equals zero. The search scans rates from about −99.99% to 1,000,000% and refines each sign change by bisection, so streams with several rates report all of them (up to five). Annualised rate = (1 + r)^periods per year − 1. Needs at least one negative and one positive flow, assumes flows at period ends, and the IRR implicitly assumes reinvestment at the same rate.
See a worked example
Worked example
A fixed demonstration, separate from the values you enter above.
- Cash flows, one per period (negative = money out)
- -1000, 300, 400, 500
- Periods per year (for the annual rate)
- 1
Example result
- IRR per period
- 8.896339%
- Net present value at the first IRR
- 0 (to rounding)
- Sign changes in the cash flows
- 1
- Total paid out
- 1,000
- Total received
- 1,200
The IRR is the discount rate at which the net present value of all cash flows is zero, assuming equally spaced periods and flows at period ends. It also assumes interim cash can be reinvested at the IRR itself, which is often optimistic.