NPV & IRR Calculator
Enter your discount rate and a stream of cash flows. We compute Net Present Value, Internal Rate of Return, and payback period.
Your cost of capital or required return.
Year 0 is usually a negative number (initial investment). Add or remove rows below.
NPV & IRR Analysis
Net Present Value
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Internal Rate of Return
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Payback period
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Total undiscounted
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Cumulative discounted cash flow
Enter cash flows to see results.
What NPV and IRR tell you
- NPV > 0 means the project creates value at your discount rate. NPV < 0 means it destroys value.
- IRR is the discount rate that would make NPV exactly zero. If IRR > your cost of capital, the project is attractive.
- Payback period tells you when undiscounted cash flows turn cumulatively positive. A simpler, cruder signal.
Formulas
NPV = Σ (CFₜ / (1 + r)ᵗ) for t = 0..n
IRR solves: Σ (CFₜ / (1 + IRR)ᵗ) = 0
Caveats
- IRR can have multiple solutions if cash flows change sign more than once. We pick the first one we find in a reasonable range.
- NPV assumes reinvestment at the discount rate. IRR assumes reinvestment at itself — often unrealistic.
- Use MIRR or scenario analysis for messier streams. This tool is for the clean case most homework and first-pass analyses actually have.