Net Present Value Calculator
Net present value is the sum of future cash flows discounted to today's value. A positive NPV means the project beats your discount rate; a negative NPV means it loses to that rate.
The NPV formula
Where C₀ is the initial outlay, Cₜ is the cash flow in year t, and r is the discount rate. The decision rule is simple: if NPV is positive, the project earns more than the discount rate and creates value; if negative, the project destroys value relative to the alternative the discount rate represents.
Choosing a discount rate
The discount rate should reflect the opportunity cost of the capital being deployed at the risk level of the cash flows being discounted. For a public company, that's typically the weighted-average cost of capital (WACC). For a private project, it's the rate the company could earn on alternatives of similar risk — often expressed as a hurdle rate. Inflating the discount rate to compensate for risky cash flows is a common shortcut; cleaner practice is to discount expected cash flows at the cost of capital and adjust for risk via scenarios.
Worked example
A factory upgrade costs $500,000 today and is expected to produce $130,000 of incremental cash flow each year for five years. At a 10% discount rate: PV of the five cash flows is $492,815, NPV is −$7,185 — barely negative. At an 8% discount rate, NPV becomes +$19,054. The same project is acceptable or rejectable based on which rate you require, which is why discount rate selection is a real strategic decision.
What NPV doesn't account for
- Optionality. Standard NPV treats the project as a fixed commitment; in reality, you can often delay, expand, or abandon. Real options analysis values these flexibilities.
- Strategic positioning. Cash flows might depend on whether you build the capability — e.g., a barely NPV-positive entry into a market may unlock a large NPV-positive expansion later.
- Cash flow uncertainty. NPV is a single point estimate. Pair it with sensitivity analysis on the riskiest two or three inputs.
- Capital structure assumptions. Using WACC implicitly assumes the project is financed at the company's existing debt-equity mix.