29 CFR § 548.303 - Average earnings for each type of work.
(a) Section 548.3(c) authorizes as an established basic rate: “A rate per hour which is obtained by averaging the earnings, exclusive of payments described in paragraphs (1) through (7) of section 7(e) of the act, of the employee for each type of work performed during each workweek, or any other longer period not exceeding sixteen calendar days, for which such average is regularly computed under the agreement or understanding. Such a rate may be used to compute overtime compensation, during the particular period for which such average is computed, for all the overtime hours worked by the employee at the type of work for which the rate is obtained.”
(b) Section 548.3(c) differs from § 548.3(b) in this way: Section 548.3(b) provides for the computation of the basic rate on the average of all earnings during the specified period; § 548.3(c) permits the basic rate to be computed on the basis of the earnings for each particular type of work. Thus, if the employee performs different types of work, each involving a different rate of pay such as different piece-rate, job rates, or a combination of these with hourly rates, a separate basic rate may be computed for each type of work and overtime computed on the basis of the rate or rates applicable to the type of work performed during the overtime hours.