About NPV / IRR Calculator
Net present value (NPV) is the sum of all cash flows discounted to today: NPV = Σ CFt ÷ (1 + r)^t, with the first value at t = 0 undiscounted. The internal rate of return (IRR) is the rate at which NPV equals zero; it is found by bisection between −99% and 1,000% and needs at least one negative and one positive cash flow. Periods are assumed to be evenly spaced. Not investment advice.
How to use NPV / IRR Calculator
- Type or paste into the "Cash flow per period (period 0 first, one per line)" box, or press "Use example" to try it with sample data.
- Set "Discount rate per period" if the defaults do not fit.
- The result appears below and updates as you type.
- Copy the result with the copy button, or download it as a file where that is offered.
Questions about NPV / IRR Calculator
What does a positive NPV mean?
The discounted inflows exceed the outflows, so the project is expected to earn more than the discount rate you entered. A negative NPV means it earns less than that rate.
Why is the IRR not found?
An IRR exists only if the cash flows include both money out and money in, and the rate lies between −99% and 1,000%. Cash flows that change sign more than once can also have several IRRs; only one is reported.
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