The federal rule
The Contract Work Hours and Safety Standards Act sets a 40-hour standard workweek. Hours over 40 in a workweek must be paid at no less than 1.5 times the basic rate of pay (40 U.S.C. 3702).
- Which contracts. The Act doesn't apply to contracts of $100,000 or less (40 U.S.C. 3701). Contracts that get federal money under a Related Act are covered above $100,000. Direct federal contracts under the FAR get the overtime clause above $200,000 (48 CFR 22.305). If your contract includes the clause, it applies.
- Basic rate means base, not total. Fringe payments are left out of the overtime math, including cash paid in lieu of fringe. But the overtime base can never be lower than the base rate on the wage determination (29 CFR 5.32).
- The FLSA applies too. It also requires 1.5 times the regular rate for hours over 40, and it counts all hours for the employer that week (29 CFR 778.103).
Get the base and fringe from your wage determination. The prevailing wage calculator turns them and the week's hours into straight-time and overtime pay.
Example: one classification
A carpenter's determination lists a $44.00 base and a $22.50 fringe (illustrative numbers). The contractor pays the fringe into plans. The carpenter works 10, 10, 8, 10 and 8 hours, Monday to Friday: 46 hours, so 6 are overtime.
| Item | Math | Amount |
|---|---|---|
| Straight time | 40 × $44.00 | $1,760.00 |
| Overtime | 6 × ($44.00 × 1.5 = $66.00) | $396.00 |
| Fringe, every hour | 46 × $22.50 | $1,035.00 |
| Total cost | $3,191.00 |
One overtime hour costs $66.00 + $22.50 = $88.50. Multiplying the full $66.50 package by 1.5 gives $99.75, which overpays by $11.25 an hour. Paying fringe on only 40 hours underpays by 6 × $22.50 = $135.00. The fringe benefits guide covers how to take plan credit.
Cash in lieu and above-scale pay
All cash. Same carpenter, no plans: the contractor pays $66.50 an hour in cash, $44.00 base plus $22.50 in lieu of fringe. The cash in lieu is still excluded from overtime (29 CFR 5.32(c)(1)). The overtime premium is half the base: 6 × $22.00 = $132.00. Pay is 46 × $66.50 = $3,059.00, plus $132.00, for $3,191.00. That matches the total above. An overtime hour is still $88.50, not $66.50 × 1.5 = $99.75.
One catch: if the "cash in lieu" is really the worker's normal wage, such as the rate you pay them on private jobs with no fringe, it counts as base, and overtime is figured on it (29 CFR 5.32(c); DOL's Resource Book).
Base above scale. If you pay the carpenter $48.00 base when the determination says $44.00, overtime is figured on the $48.00 you actually pay (29 CFR 5.32(c)(2)). Overtime is $72.00 an hour, plus the $22.50 fringe at straight time: $94.50. Paying $66.00 would short the worker $6.00 per overtime hour.
Two classifications in one week
When a worker does two kinds of work at two rates, DOL's Prevailing Wage Resource Book shows two ways to figure overtime on Davis-Bacon work. Illustrative rates: laborer $30.00 base, $18.00 fringe; operator $42.00 base, $24.00 fringe. The worker does laborer work Monday to Wednesday (30 hours) and runs equipment Thursday and Friday (20 hours). That is 50 hours: 10 overtime, all on Friday as an operator.
| Step | Weighted average | Rate in effect |
|---|---|---|
| Straight-time pay, all 50 hours | 30 × $30.00 + 20 × $42.00 = $1,740.00 | $1,740.00 |
| Rate the premium is based on | $1,740.00 ÷ 50 = $34.80 | $42.00 (operator, the work done in the overtime hours) |
| Overtime premium, 10 hours × half the rate | 10 × $17.40 = $174.00 | 10 × $21.00 = $210.00 |
| Cash wages | $1,914.00 | $1,950.00 |
| Fringe at straight time | 30 × $18.00 + 20 × $24.00 = $1,020.00 | $1,020.00 |
| Total | $2,934.00 | $2,970.00 |
- Weighted average is the default. Total straight-time earnings at all rates, divided by all hours (29 CFR 778.115).
- Rate in effect needs an agreement with the worker before the work. The rate must be the one actually paid for that work in non-overtime hours, and the hours paid at overtime must cover all hours over 40 (29 CFR 778.419).
PrevailCrew's overtime check accepts either method on federal jobs. If the rate in effect pays less than the weighted average, it warns you that this needs the worker's prior agreement. Which costs more depends on the work done in the overtime hours. Had those 10 hours been laborer work, rate in effect would give a $150.00 premium. Either way, fringe isn't part of the math.
California daily overtime
California public works add a daily rule. Labor Code 1811 limits a worker to 8 hours a day and 40 a week. Section 1815 allows longer days and weeks if every hour over 8 in a day is paid at no less than 1.5 times the basic rate. Under section 1813, a contractor that works someone past those limits in violation of the article forfeits $25 per worker per day.
Example (illustrative): $50.00 base, $30.00 employer payments, and a week of 10, 10, 8, 8 and 4 hours. That is 40 hours, so no weekly overtime. But Monday and Tuesday each have 2 hours over 8.
| Item | Math | Amount |
|---|---|---|
| Straight time | 36 × $50.00 | $1,800.00 |
| Daily overtime | 4 × $75.00 | $300.00 |
| Employer payments, every hour | 40 × $30.00 | $1,200.00 |
| Total | $3,300.00 |
Use the determination's overtime columns. California determinations print the overtime rates for you. The Iron Worker determination C-20-X-1-2026-2 (issued August 22, 2026), Area 1, lists a $58.44 base and $39.12 in employer payments. Its daily overtime rate is $126.78: $58.44 × 1.5 = $87.66, plus $39.12. Its Sunday/holiday rate is $156.00: $58.44 × 2 = $116.88, plus $39.12. So these columns already include the employer payments at straight time. Don't add the fringe again.
The tiers come from each craft's determination, not the statute. In this one, 1.5 times applies to the first 2 daily overtime hours and the first 8 hours on Saturday, and all other overtime is at the Sunday/holiday rate. The determination also says which holidays count. Check the footnotes and the holiday provisions for your craft on DIR's determinations page, and use the determination in effect for your job. More in California certified payroll.
Overtime on the WH-347
On the 2025 WH-347 (see the WH-347 instructions), using the single classification example:
- Column 4: daily hours, straight time on the ST line and overtime on the OT line. The week passes 40 on Friday, so Friday shows 2 ST and 6 OT.
- Column 5: 40 ST and 6 OT, 46 in total.
- Column 6A: $44.00 on top, $66.00 below. Leave cash in lieu out of 6A.
- Column 6B: 46 × $22.50 = $1,035.00. Overtime hours get fringe credit at straight time. In the all-cash version, the same $1,035.00 goes in 6C instead.
- Column 7A: $1,760.00 + $396.00 = $2,156.00 with plans. With cash in lieu, add the $1,035.00: $3,191.00.
Two classifications get two rows with the same worker number. Put the overtime hours on the row for the work done in them. In the two-classification example, the operator row shows 20 hours in column 5 (10 ST, 10 OT) and, in 6A, $42.00 on top and $59.40 below with weighted average ($42.00 + $17.40), or $63.00 with rate in effect. The laborer row shows 30 ST hours, $30.00, and no OT. The form has no double-time line, so ask the agency how it wants double time shown. The free WH-347 builder fills these columns from hours and rates.
Common mistakes
- Multiplying the fringe. 1.5 times the total package overpays. 1.5 times the base and nothing for fringe underpays. The fringe is owed for every hour at straight time.
- Treating cash in lieu as base. It isn't in the overtime math, and it stays out of column 6A.
- Figuring overtime on the determination base when you pay more. Use the rate you actually pay.
- Missing the 40 across rows. A worker split across classifications, or across covered jobs, can pass 40 even when no single row does. For the FLSA, private work that week counts too.
- Skipping California's daily 8. A 40-hour week can still owe overtime.
- Adding fringe to a California overtime column. It's already in there.