Net Present Value Calculator
Calculate net present value from a list of cash flows and a discount rate, with IRR, profitability index and a full discounting table.
- Net present value (NPV)
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- PV of future cash flows
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- Internal rate of return (IRR)
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- Profitability index
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- Discounted payback
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- Undiscounted net cash
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Period-by-period discounting
| Period | Cash flow | Discount factor | Present value | Cumulative PV |
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How it works
This calculator uses the standard discounted cash flow (DCF) definition of net present
value: NPV = -C₀ + Σ CFₜ / (1 + r)ᵗ for t = 1…n, where C₀ is the
initial investment paid at period 0, CFₜ is the cash flow received at the
end of period t and r is the discount rate for one period. With a
$10,000 investment, a 10% rate and cash flows of 3,000, 4,200 and 6,800, the present values
are 2,727.27, 3,471.07 and 5,108.94 — a total of 11,307.29, so the NPV is
$1,307.29. A positive NPV means the project is expected to earn more than
your required return; a negative NPV means it destroys value at that rate.
Enter one cash flow per line starting with period 1 (commas work too). Use a minus sign for
money going out, e.g. -1500, and leave out thousands separators. The initial
investment is the cash paid at period 0 and is already treated as money going out, so enter
it as a positive number.
The page also reports the internal rate of return (the discount rate that makes NPV exactly zero, found by bisection and shown only when the cash flows change sign), the profitability index (present value of future flows ÷ initial investment) and the discounted payback period, interpolated within the period where cumulative present value first turns positive. Make sure your rate matches your period: a 12% annual rate is roughly 1% per month, not 12%. Everything is computed in JavaScript inside your browser — no sign-up, no ads and no numbers sent to a server. Results are estimates and ignore tax and inflation.
Frequently asked questions
How is net present value calculated?
This tool uses the standard discounted cash flow formula NPV = -C₀ + Σ CFₜ / (1 + r)ᵗ for t = 1…n, where C₀ is the initial investment at period 0, CFₜ is the cash flow at the end of period t and r is the discount rate for one period. With a $10,000 investment at 10% and cash flows of 3,000, 4,200 and 6,800, the present values are 2,727.27, 3,471.07 and 5,108.94, giving an NPV of $1,307.29.
What does a positive or negative NPV mean?
A positive NPV means the discounted cash flows are worth more than the money you put in, so the project is expected to beat your required return at that discount rate. A negative NPV means it falls short. Exactly zero means it earns your required return and nothing more — the discount rate at that point is the internal rate of return.
Do my numbers leave my device?
No. Every calculation runs in JavaScript in your browser, with no sign-up, no ads and no server call, so you can model real budgets and deals safely. Results are estimates for planning only and ignore tax, inflation and financing fees.