A defined benefit pension plan is a major type of pension plan in which an employer promises a specified monthly benefit on retirement that is predetermined by a formula based on the employee's earnings history, tenure of service and age, rather than depending on investment returns. The most common type of formula used is based on the employee’s terminal earnings. Under this formula, benefits are based on a percentage of average earnings during a specified number of years at the end of a worker’s career. In the private sector, defined benefit plans are typically funded exclusively by employer contributions. For very small companies with one owner and a handful of younger employees, the business owner generally receives a high percentage of the benefits. In the public sector, defined benefit plans often require employee contributions.