A Practice Note discussing the fluctuating workweek (FWW) method of calculating overtime pay under the federal Fair Labor Standards Act (FLSA), including the requirements for using the FWW method and when the FWW method may be used to calculate overtime pay damages in FLSA misclassification cases. This Note addresses federal law. State and local law may impose different or additional requirements, including by prohibiting or restricting use of the FWW method.