In theory, an NPV is “good” if it is greater than zero. After all, the NPV calculation already takes into account factors such as the investor’s cost of capital, opportunity cost, and risk tolerance through the discount rate. And the future cash flows of the project, together with the time value of money, are also captured. Therefore, even an NPV of $1 should theoretically qualify as “good,” indicating the project is worthwhile. In practice, since estimates used in the calculation are subject to error many planners will set a higher bar for NPV to give themselves an additional margin of safety.