Overtime on Biweekly and Semi-Monthly Payroll: The Workweek Rule

Short answer: overtime is calculated for each fixed 7-day workweek. A biweekly or semi-monthly pay period never changes that: 50 hours one week and 30 the next is 10 overtime hours, even though the two-week total is exactly 80. Run the week through the FLSA Overtime Calculator.

The rule: one workweek at a time

The FLSA "takes a single workweek as its standard and does not permit averaging of hours over 2 or more weeks" (29 CFR §778.104). A workweek is a fixed, regularly recurring period of 168 hours — seven consecutive 24-hour periods — that the employer chooses and keeps (29 CFR §778.105). It can start on any day and at any hour, but it cannot be shifted to avoid overtime.

Biweekly payroll (every two weeks)

A biweekly pay period contains exactly two workweeks, so the arithmetic is simple — as long as each week is calculated separately.

Example: $22/hour, week 1 = 50 hours, week 2 = 30 hours.

Correct paycheck: $1,870. A system that only looks at the 80-hour total would pay 80 × $22 = $1,760 — $110 short every time the hours are uneven. Over a year of similar fortnights, that is the kind of recurring error that turns into a back-pay claim; see the Back Pay Calculator.

Semi-monthly payroll (1st–15th, 16th–end)

Semi-monthly periods have 11, 13, 15 or 16 days, so a workweek often straddles two pay periods. The overtime still belongs to the workweek, and it is due on the regular payday for the period in which that workweek ends (29 CFR §778.106).

Example: workweek Sunday 13 – Saturday 19, 46 hours, $20/hour. Pay periods are 1–15 and 16–end of month.

1. Count the full workweek: 46 hours → 6 overtime hours.
2. The workweek ends on the 19th, inside the second pay period.
3. The 6 overtime hours (6 × $30 = $180, or the $60 premium on top of straight time already paid) are due on the payday for the 16th–end period.

Hours worked on the 13th–15th are still paid at straight time in the first period. What matters is that the overtime for that workweek is paid no later than the payday of the period in which the week ends.

When overtime can be paid late

If the overtime amount cannot be known by the regular payday — for example, a monthly production bonus that changes the regular rate — the employer may pay the extra overtime "as soon after the regular pay period as is practicable," but never later than the next payday after the computation can be made (29 CFR §778.106).

Salaried non-exempt employees

A salaried employee who is not exempt is owed overtime the same way. Convert the salary to a weekly amount first. A semi-monthly salary covers 24 periods a year, so the weekly equivalent is the semi-monthly salary × 24 ÷ 52 (29 CFR §778.113(b)). If the salary is meant to cover a fluctuating number of hours, see the Fluctuating Workweek Calculator.

State rules can be stricter

Some states count overtime by the day as well as by the week — California owes daily overtime after 8 hours and double time after 12 (Labor Code §510). Use the California Overtime Calculator for those workweeks.

Sources

• 29 CFR §778.104 — each workweek stands alone
• 29 CFR §778.105 — determining the workweek
• 29 CFR §778.106 — time of payment
• 29 CFR §778.113 — salaried employees, general
• California Labor Code §510