Residual income is income that a person continues to make after the work he has put into a project has been completed. Residual income is different from linear income in that linear income refers to someone’s salary. Salaries are paid based on the number of hours someone works in the present, rather than the royalties someone can earn on work that was done in the past. To explore this concept, consider the following residual income definition.
Establishing residual income allows you to accumulate wealth faster, have a more flexible lifestyle and maintain a diverse financial portfolio. As with any successful investment, hard work is required. With residual income, however, that work tends to be upfront. Once your revenue stream is established, the work and time involved is significantly lower than active income sources. With residual income, you’ll secure funds for your future, have a better idea of where you stand financially and enjoy peace of mind knowing you’re maintaining lucrative, long-term investments.  

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.