Wherever in this article the term "wages" is used, it shall be construed to mean the average weekly wages of the employe, ascertained as follows:
The terms "average weekly wage" and "total wages," as used in this section, shall include board and lodging received from the employer, and gratuities reported to the United States Internal Revenue Service by or for the employe for Federal income tax purposes, but such terms shall not include amounts deducted by the employer under the contract of hiring for labor furnished or paid for by the employer and necessary for the performance of such contract by the employe, nor shall such terms include deductions from wages due the employer for rent and supplies necessary for the employe's use in the performance of his labor, nor shall such terms include fringe benefits, including, but not limited to, employer payments for or contributions to a retirement, pension, health and welfare, life insurance, social security or any other plan for the benefit of the employe or his dependents: Provided, however, That the amount of any bonus, incentive or vacation payment earned on an annual basis shall be excluded from the calculations under clauses (a) through (d.2). Such payments if any shall instead be divided by fifty-two and the amount shall be added to the average weekly wage otherwise calculated under clauses (a) through (d.2).
Where the employe is working under concurrent contracts with two or more employers, his wages from all such employers shall be considered as if earned from the employer liable for compensation.
77 P.S. § 582