Residual income is money that is earned on a recurring basis, typically as the result of a single original action. Rather than earning an hourly wage, residual income is typically generated through an initial investment of time or money with the goal of earning continuous payments. Once the initial investment, product, or service is made, the ongoing income that is earned is generally passive in nature.
Residual income is calculated as net income less a charge for the cost of capital. The charge is known as the equity charge and is calculated as the value of equity capital multiplied by the cost of equity or the required rate of return on equity. Given the opportunity cost of equity, a company can have positive net income but negative residual income.