FLSA vs. California overtime, explained
This calculator implements two overtime rule sets: federal FLSA weekly overtime, and California daily overtime. They're not interchangeable, and the second doesn't replace the first — it stacks on top of it. The examples below are computed against the same code the calculator runs, not invented numbers.
Federal law: weekly overtime (the default for 49 states)
The Fair Labor Standards Act (FLSA) sets a single federal threshold: non-exempt employees get paid time-and-a-half for every hour worked over 40 in a workweek. There's no federal daily rule — a 12-hour day and a 4-hour day both count as ordinary hours toward that 40, as long as the week's total stays under it. This is the "Weekly (FLSA)" mode in the calculator above, and it's the only overtime rule that applies by default in every state except a handful — California among them — that layer something stricter on top.
Example: a 45-hour week, weekly rule, $20/hr
California: daily overtime, stacked on top of weekly
California Labor Code Section 510 adds a daily threshold that most states don't have: time-and-a-half for hours worked over 8 in a single day, and double time for hours over 12 in a single day. The same section keeps the weekly 40-hour rule in force at the same time — it's an "and," not a "replaces." The calculator's "Daily (California)" mode runs both checks: each day is bucketed into regular/1.5×/2× first, and then the week's regular-hour total is capped at 40, with anything over that reclassified as overtime even if no single day crossed 8 hours.
Example: one 13-hour day, California daily rule, $20/hr
The mistake people actually make
The most common error isn't in the daily math — it's assuming the daily rule is the whole California calculation, and that a week where no single day exceeds 8 hours can't owe overtime. It can. The weekly 40-hour threshold still applies as a backstop on top of the daily buckets, and it can trigger even when every individual day looks perfectly ordinary:
Example: six 8-hour days (48 hrs/week), California daily rule, $20/hr
No single day exceeds 8 hours, so the daily rule alone would call this 48 hours of straight time. The weekly 40-hour check still applies on top:
The second common mistake is assuming daily overtime is a normal feature of U.S. labor law. It isn't. Most states run on the federal weekly-only baseline described above. A few others — Alaska, Nevada, and Colorado among them — have some form of daily overtime with their own thresholds and exceptions, distinct from California's. This calculator doesn't model those; it implements FLSA weekly and California daily specifically, and picking "Daily (California)" for a shift in one of those other states will produce the wrong number.
What this tool doesn't cover
A few things worth knowing before relying on this for a real paycheck or a dispute:
- Other states' daily-overtime rules (Alaska, Nevada, Colorado, and a few others) aren't implemented — only FLSA weekly and California daily.
- Both modes here use a single flat hourly rate as the "regular rate of pay." Federal law actually requires certain non-discretionary bonuses and commissions to be folded into that rate before overtime is calculated, which this calculator doesn't do.
- Union contracts (CBAs) commonly negotiate their own overtime terms that override the statutory default — this tool has no way to know what's in a specific contract.
- Whether an employee is exempt from overtime at all (salaried, executive, professional, and other exemption categories) isn't something this calculator determines — it assumes non-exempt status.
None of this is legal advice — see the terms for the full disclaimer. If a calculation here affects a real paycheck, check it against your employer's payroll department or your state labor agency.