NPV Calculator

As taught in the CFA Institute curriculum, NPV directly measures the dollar value an investment creates — not a percentage, not a payback time, but actual currency value added. It correctly handles any cash flow pattern, properly discounts future dollars to today's value, and gives an unambiguous accept/reject signal.

Other metrics like IRR, ROI, or payback period have important roles, but they all have edge cases where they mislead. NPV doesn't. It's the metric every MBA finance class teaches first and every CFO uses last.

The biggest decision you'll make in NPV analysis isn't the cash flow estimates — it's the discount rate. A small change in rate (10% → 12%) can flip a positive NPV to negative.

Always document your discount rate assumption and run sensitivity analysis with at least three rates:

• optimistic (low)
• base case
• pessimistic (high)

If NPV stays positive across all three, the project is robust. If it flips, you need better cash flow estimates or a different project.

NPV sums every future cash flow discounted to today, then subtracts the initial investment: NPV = Σ [Cash Flow_t ÷ (1 + r)^t] − Initial Investment.

For a $100,000 investment returning $30,000 a year for five years at a 10% discount rate, each year's cash flow is divided by 1.10 raised to that year's power, giving an NPV of about $13,724. A positive result means the project earns more than your 10% required return.

The discount rate represents your opportunity cost of capital and is the single most important NPV input.

• Companies typically use their weighted average cost of capital (WACC), often 8–12%
• real estate investors use 6–10%
• venture investors much higher

Setting the rate too low overstates value and approves bad projects; too high rejects good ones. When unsure, calculate NPV across a range of rates rather than betting on a single number.

NPV and IRR usually agree on whether to accept a project, but they can conflict when ranking mutually exclusive projects of different sizes or cash-flow timing.

NPV measures absolute dollar value created and is the more reliable tie-breaker, while IRR expresses return as a percentage. When they disagree, finance theory says to follow NPV because it directly maximizes shareholder wealth.

Use our IRR calculator alongside this tool to see both perspectives.

The rule is simple: accept any independent project with a positive NPV and reject any with a negative NPV.

• A positive NPV means the investment returns more than your required rate and adds wealth in today's dollars
• a zero NPV means it exactly meets your hurdle rate

For competing projects you can only choose one of, pick the highest positive NPV.

Real investments rarely produce identical annual cash flows, and NPV handles this naturally because each period is discounted individually.

You can model a project that loses money in year one, breaks even in year two, and generates large inflows later — simply enter each year's actual cash flow.

This flexibility is why NPV is preferred for complex, lumpy investments where simpler metrics break down.

The profitability index (PI) divides the present value of future cash flows by the initial investment, expressing efficiency as a ratio.

A PI above 1.0 corresponds to a positive NPV; a PI of 1.3 means each dollar invested returns $1.30 in present-value terms.

PI is especially useful for capital rationing — ranking projects when your budget can't fund every positive-NPV opportunity.

Standard payback period counts how long until cumulative cash flows recover the investment, ignoring the time value of money.

Discounted payback first discounts each cash flow, then measures recovery time, giving a more conservative and realistic figure.

Both are useful liquidity and risk screens, but neither should replace NPV as the primary accept-or-reject metric.

NPV is the backbone of corporate capital budgeting because it ranks competing projects by the actual dollar value each creates.

CFOs use it to choose between:

• building a new plant
• acquiring a competitor
• buying back stock

Because NPV is additive, the combined NPV of selected projects equals the total value created — a property no percentage-based metric shares.

Because NPV is highly sensitive to the discount rate, serious analysis tests several rates rather than one.

The same $100,000 project that shows an NPV of $13,724 at 10% can turn negative near 13%, revealing how much margin for error you have.

Running NPV at low, base, and high discount rates exposes how robust an investment is before you commit capital.

Frequent NPV errors include:

• using an arbitrary discount rate
• forgetting to include terminal or salvage value
• mixing nominal cash flows with a real discount rate
• ignoring inflation or taxes

Another mistake is treating sunk costs as relevant — only future, incremental cash flows belong in an NPV. Clean inputs and a justified discount rate matter more than decimal precision.