29 C.F.R. § 778.113 : Labor — REGULATIONS RELATING TO LABOR — WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR — STATEMENTS OF GENERAL POLICY OR INTERPRETATION NOT DIRECTLY RELATED TO REGULATIONS — OVERTIME COMPENSATION — THE OVERTIME PAY REQUIREMENTS —PRINCIPLES FOR COMPUTING OVERTIME PAY BASED ON THE "REGULAR RATE" — Salaried employees-general

(a) Weekly salary. If the employee is employed solely on a weekly salary basis, the regular hourly rate of pay, on which time and a half must be paid, is computed by dividing the salary by the number of hours which the salary is intended to compensate. If an employee is hired at a salary of $350 and if it is understood that this salary is compensation for a regular workweek of 35 hours, the employee's regular rate of pay is $350 divided by 35 hours, or $10 an hour, and when the employee works overtime the employee is entitled to receive $10 for each of the first 40 hours and $15 (one and one-half times $10) for each hour thereafter. If an employee is hired at a salary of $375 for a 40-hour week the regular rate is $9.38 an hour.
(b) Salary for periods other than workweek. Where the salary covers a period longer than a workweek, such as a month, it must be reduced to its workweek equivalent. A monthly salary is subject to translation to its equivalent weekly wage by multiplying by 12 (the number of months) and dividing by 52 (the number of weeks). A semimonthly salary is translated into its equivalent weekly wage by multiplying by 24 and dividing by 52. Once the weekly wage is arrived at, the regular hourly rate of pay will be calculated as indicated above. The regular rate of an employee who is paid a regular monthly salary of $1,560, or a regular semimonthly salary of $780 for 40 hours a week, is thus found to be $9 per hour. Under regulations of the Administrator, pursuant to the authority given to him in section 7(g)(3) of the Act, the parties may provide that the regular rates shall be determined by dividing the monthly salary by the number of working days in the month and then by the number of hours of the normal or regular workday. Of course, the resultant rate in such a case must not be less than the statutory minimum wage.

29 C.F.R. §778.113

46 FR 7310, 1/23/1981, as amended at 76 FR 18857, 4/5/2011