Section 309. Wherever in this article the term "wages" is used, it shall be construed to mean the average weekly wages of the employee, ascertained as follows:
(a) If at the time of the injury the wages are fixed by the week, the amount so fixed shall be the average weekly wage;
(b) If at the time of the injury the wages are fixed by the month, the average weekly wage shall be the monthly wage so fixed multiplied by twelve and divided by fifty-two;
(c) If at the time of the injury the wages are fixed by the year, the average weekly wage shall be the yearly wage so fixed divided by fifty-two;
(d) If at the time of the injury the wages are fixed by any manner not enumerated in clause (a), (b) or (c), the average weekly wage shall be calculated by dividing by thirteen the total wages earned in the employ of the employer in each of the highest three of the last four consecutive periods of thirteen calendar weeks in the fifty-two weeks immediately preceding the injury and by averaging the total amounts earned during these three periods.
(d.1) If the employee has not been employed by the employer for at least three consecutive periods of thirteen calendar weeks in the fifty-two weeks immediately preceding the injury, the average weekly wage shall be calculated by dividing by thirteen the total wages earned in the employ of the employer for any completed period of thirteen calendar weeks immediately preceding the injury and by averaging the total amounts earned during such periods.
(d.2) If the employee has worked less than a complete period of thirteen calendar weeks and does not have fixed weekly wages, the average weekly wage shall be the hourly wage rate multiplied by the number of hours the employee was expected to work per week under the terms of employment.
(e) Except as provided in clause (d.1) or (d.2), in occupations which are exclusively seasonal and therefore cannot be carried on throughout the year, the average weekly wage shall be taken to be one-fiftieth of the total wages which the employee has earned from all occupations during the twelve calendar months immediately preceding the injury, unless it be shown that during such year, by reason of exceptional causes, such method of computation does not ascertain fairly the earnings of the employee, in which case the period for calculation shall be extended so far as to give a basis for the fair ascertainment of his average weekly earnings.
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 employee 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 employee, nor shall such terms include deductions from wages due the employer for rent and supplies necessary for the employee’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 employee 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 employee 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.

(309 amended June 24, 1996, P.L.350, No.57)

Compiler's Note: Section 32.1 of Act 57 of 1996, which amended section 309, provided that the amendment of section 309 shall apply only to claims for injuries, which are suffered, on or after the effective date of section 32.1.