Inclusion is settled; the method is where California diverges
The components page established that a nondiscretionary bonus belongs in the regular rate. This page addresses the question that inclusion leaves open: how the bonus is converted into an addition to the overtime rate. The answer is not obvious, because a bonus is earned over a span of hours rather than at an hourly rate, so the bonus has to be apportioned to hours before it can be priced into overtime — and the apportionment can be done in more than one way. The choice of method is not a rounding detail; for a flat-sum bonus, the California method produces a materially larger overtime figure than the federal one, and using the wrong method understates the overtime on every such bonus the employer pays.
The divergence is specific to flat-sum bonuses — a fixed amount that does not vary with the number of hours worked, such as a $100 attendance bonus or a flat weekend-shift bonus. For these, Alvarado v. Dart Container prescribes a method that differs from the federal regulation on two points at once: the divisor used to find the bonus's per-hour value, and the multiplier applied to the overtime hours. Production and percentage bonuses, which scale with output or earnings, are treated differently and may follow the federal method. The sections below set the discretionary line briefly, state the Alvarado method, distinguish the bonus types, and let the computation be run.
The bonuses this rule reaches
The flat-sum method applies only to bonuses that must be included in the rate in the first place — that is, to nondiscretionary bonuses, as the components page develops at length. The short version bears repeating because it defines the population: a bonus is nondiscretionary, and therefore includable, unless both the fact of payment and the amount are in the employer's sole discretion and the bonus is not paid pursuant to any prior promise or expectation. Attendance bonuses, weekend-shift bonuses, and fixed performance bonuses announced in advance are nondiscretionary, however the employer labels them, because the employee can earn them by satisfying a known condition. A genuinely discretionary, unannounced gift is excluded and never reaches the computation. The flat-sum question therefore arises for precisely the bonuses restaurants most commonly pay — the announced, conditioned, fixed-dollar incentives — and it arises for the whole population that receives them.
Spread over non-overtime hours, paid at time and a half
In Alvarado v. Dart Container, the employer paid a flat $15 attendance bonus for completing a weekend shift and computed the overtime on it using the federal method. The California Supreme Court held that method incorrect for a flat-sum bonus and prescribed a different one. The bonus's per-hour value is found by dividing the bonus by the number of non-overtime hours the employee actually worked in the period — not by all hours worked, and not by the fixed number of non-overtime hours that exist in the period. And the overtime due on the bonus is then computed at one and one-half times that per-hour value for each overtime hour — not the half-time premium the federal regulation uses. Both choices move in the employee's favor, and together they produce a substantially larger overtime figure than the federal method yields.
The reasoning behind the two choices is coherent once seen together, and it tracks the statute the Court was construing — Labor Code section 510(a), which sets overtime at one and one-half times the ‘regular rate of pay,’ read through California’s settled canon that wage protections are construed in the employee’s favor. Apportioning the bonus over non-overtime hours only reflects a judgment that a flat-sum bonus compensates the employee's regular, non-overtime work — so the bonus does not "reach" the overtime hours at straight time the way an hourly wage does. Because the overtime hours received none of the bonus at straight time, the full time-and-a-half of the per-hour value is owed for each overtime hour, rather than only the half-time premium that suffices when straight time has already been paid. The Court adopted the formula the Division of Labor Standards Enforcement had set out in its enforcement manual, and — critically — applied it retroactively, so the method governs not only future bonuses but the historical periods in which a flat-sum bonus was paid under the federal formula.
Two departures from federal law in one rule: divide by non-overtime hours, and pay time and a half — not total hours and a half-time premium. Both favor the employee, and both reach back.
The method depends on the kind of bonus
Alvarado's method is keyed to the flat-sum character of the bonus, and that limit matters because not every nondiscretionary bonus is flat-sum. A flat-sum bonus is a fixed amount that does not vary with hours worked — earned by meeting a condition, paid in the same dollar amount whether the employee worked thirty hours or fifty. A production or percentage bonus, by contrast, scales with output, sales, or hours — a piece-rate incentive, a percentage of sales, a bonus that grows with the hours or units worked. For those, the rationale that the bonus compensates only non-overtime work does not hold in the same way, and the federal apportionment method — dividing by all hours worked and applying the half-time premium — may apply. The distinction is therefore not academic: it determines which formula is correct, and applying the flat-sum method to a production bonus, or the production method to a flat-sum bonus, misstates the overtime in opposite directions.
For a restaurant, the practical task is to classify each bonus by its structure before computing it. The fixed attendance, weekend, and holiday bonuses common in the industry are flat-sum and take the Alvarado method. A bonus tied to sales volume, covers, or tips, or one that scales with hours, is more likely a production or percentage bonus that may take the federal method. Where a bonus has mixed features, the safer course is to analyze its dominant character and document the basis for the method chosen, because the computation is auditable and a plaintiff will scrutinize whether the flat-sum method was applied to the flat-sum bonuses. The classification drives the formula, and the formula drives the exposure.
The flat-sum overtime, both ways
The calculator computes the overtime due on a flat-sum bonus under the Alvarado method and, beside it, the figure the federal method would produce — the gap being the per-bonus underpayment a federal formula creates. Enter the bonus and the hours for a single employee in a single period; the difference scales across every employee and every period in which the bonus was paid.
Fig. 1. Illustrative. Alvarado v. Dart Container Corp. (2018) 4 Cal.5th 542; cf. 29 C.F.R. § 778.110. The Alvarado method governs flat-sum bonuses; production/percentage bonuses may use the federal method (§ IV). The figure prices the bonus's overtime only; the base-wage overtime is separate. Daily overtime and double-time are not modeled; figures are hypothetical.
The federal formula, applied to a California bonus
The characteristic error is mechanical and systematic: a payroll system configured to the federal standard — or a multistate employer applying one national method — computes overtime on flat-sum bonuses by dividing over all hours and applying the half-time premium, understating the overtime on every flat-sum bonus by the gap the calculator shows. Because the error is in the formula, it recurs on every bonus, for every employee, in every period, and it does so invisibly, since the employer is paying some bonus overtime and the shortfall is buried in the method. The per-bonus difference looks small, but a restaurant that pays a weekly attendance or weekend bonus to a large hourly staff repeats the error thousands of times across the limitations period, and the aggregate is substantial.
Retroactivity compounds the exposure and removes the most natural defense. Because Alvarado applies retroactively, an employer cannot argue that it reasonably followed the federal method before the decision clarified the rule — the method has, in the eyes of the law, always been the California one, so the historical periods are exposed under it. The owed overtime itself is not excused by the employer's good faith; good faith bears on the penalties built on top, not on the wages. The remedy is therefore to correct the formula prospectively and to recompute the historical bonus overtime under Alvarado, which both stops the recurring shortfall and quantifies the past exposure precisely — and, done before a claim, builds the reasonable-steps record that caps the PAGA layer on whatever the recomputation reveals. The exposure and remediation page develops the recomputation across the class.