How biweekly overtime really works
A common payroll mistake: averaging hours across the two weeks of a biweekly pay period. The FLSA defines overtime per workweek — a fixed, recurring 168-hour period. If you work 30 hours in week one and 50 in week two, you're owed 10 hours of overtime for week two, even though the period "averages" 40. This calculator keeps each week separate, applies your overtime threshold to each, then combines them for the period totals and gross pay — the same way a payroll system does.
Biweekly vs. semi-monthly pay
| Biweekly | Semi-monthly | |
|---|---|---|
| Frequency | Every 2 weeks (usually same weekday) | Twice a month (e.g., 1st & 15th) |
| Pay periods / year | 26 (sometimes 27) | 24 |
| Hours per period | Consistent 80 (full-time) | Varies 72–96 |
| Overtime tracking | Simple — aligns with workweeks | Messy — weeks split across periods |
Roughly 43% of US private employers pay biweekly, making it the single most common schedule — which is why your pay stub usually covers exactly 80 scheduled hours.
Worked example
Dana works 36 hours in week one, then covers extra shifts in week two for 47 hours. Week one: all regular. Week two: 40 regular + 7 overtime. Period totals: 83 hours = 76 regular + 7 OT. At $22/hour: 76 × $22 + 7 × $33 = $1,903.00 gross for the period.