How to Calculate Payroll Hours

Built & reviewed by Nandu Kannan · Overtime rules cited to primary statutes

If you run payroll for hourly employees, the math is unforgiving: hours must be totaled per workweek, overtime applied at the right threshold, and two-rate weeks blended the way the FLSA prescribes — every pay period, on time. This guide walks through the full sequence a small employer or manager needs, with a worked example computed by the same engine that powers our calculators.

Overtime under the FLSA is always computed per individual workweek — an employee who works 50 hours then 30 hours is owed 10 overtime hours, even though the two-week average is exactly 40.

Step 1: Total each employee's hours by workweek

Define a fixed workweek (any 168-hour cycle — say, Monday 12:00 AM to Sunday 11:59 PM) and keep it consistent. For each day, net hours are time out − time in − unpaid breaks, converted to decimal (minutes ÷ 60). Short rest breaks of 5–20 minutes are paid time and are never deducted; bona fide meal periods of 30+ minutes where the employee is fully relieved of duty may be unpaid. Sum the days to get the weekly total.

Step 2: Split regular from overtime hours

The federal threshold is 40 hours per workweek; hours beyond that are paid at 1.5× the regular rate. Two traps:

Daily-overtime states. California (1.5× after 8h/day, 2× after 12), Alaska, Nevada, and Colorado (after 12h/day) require daily checks on top of the weekly one — see our overtime calculator, which knows every state's rules.
The regular rate includes more than base pay. Nondiscretionary bonuses, shift differentials, and commissions must be folded into the regular rate before the 1.5× multiplier is applied.

A note on rounding punches

You may round clock punches to the nearest 5 minutes, tenth of an hour, or quarter hour (29 CFR 785.48), but the rounding must wash out as neutral over time. With quarter-hour rounding, the 7-minute rule applies: 1–7 minutes round down, 8–14 round up. A system that rounds clock-ins up and clock-outs down — always in the employer's favor — fails the neutrality test and is a recurring source of collective actions. If you round, audit a sample quarterly: total rounded hours should track actual hours within noise.

Step 3: Blend rates when an employee has two jobs

When one employee works at two rates in the same week (say, 30 hours serving at $16 and 15 hours supervising at $24), overtime is owed on the weighted average, not either single rate:

Regular rate = total straight-time pay ÷ total hours
OT premium = OT hours × regular rate × 0.5

In that example: (30 × $16) + (15 × $24) = $840 for 45 hours, a blended rate of $18.67. The 5 overtime hours have already been paid at straight time inside the $840, so the additional premium is 5 × $18.67 × 0.5 = $46.67. Our blended overtime rate calculator does this weighted-average math, which most generic payroll tools skip.

Step 4: Map workweeks onto your pay period

The pay frequency you choose changes the bookkeeping, not the overtime rules:

	Biweekly	Semimonthly
Checks per year	26	24
Schedule	Every 2 weeks, same weekday	Fixed dates (e.g., 15th & last day)
Check size on a $52,000 salary	$2,000.00	$2,166.67
Hours per period	Always 2 full workweeks (80 scheduled hours)	Varies (86.67 average); periods split workweeks
Overtime handling	Clean — each check contains whole workweeks	OT must still be tracked per workweek and trued up across checks

Biweekly is the easier system for hourly staff precisely because every check holds two complete workweeks. If you pay semimonthly, a workweek will regularly straddle two checks — pay the overtime in the period when the workweek closes. Our semimonthly timesheet calculator is built for that layout.

Worked example: one employee, one week, $22.00/hour

Every figure below is computed by the calcWeek engine behind our time card calculator — not typed by hand:

Day	In	Out	Unpaid break	Hours
Monday	8:00 AM	5:00 PM	60 min	8.00
Tuesday	8:00 AM	5:30 PM	60 min	8.50
Wednesday	8:00 AM	6:30 PM	30 min	10.00
Thursday	8:00 AM	5:00 PM	60 min	8.00
Friday	8:00 AM	5:30 PM	30 min	9.00
Total				43.50

The week totals 43.50 hours (43:30): 40.00 regular + 3.50 overtime. At $22.00/hour:

Regular pay: 40.00 × $22.00 = $880.00
Overtime pay: 3.50 × $22.00 × 1.5 = $115.50
Gross for the week: $995.50

In a biweekly system this week simply pairs with the next one on a single check. In a semimonthly system, if the period ended mid-week, you would pay the days that fall inside the period at straight time and settle the 3.50 overtime hours when the workweek completes.

A closing checklist

Fixed workweek defined and documented.
Daily hours net of unpaid meal breaks only; rest breaks stay paid.
Weekly totals checked against the 40-hour line — and daily limits in CA/AK/NV/CO.
Two-rate weeks blended by weighted average.
Records kept: payroll 3 years, time cards 2 years (FLSA minimums).

Frequently asked questions

Is overtime calculated per pay period or per workweek?

Per workweek, always. The FLSA defines overtime as hours over 40 in a fixed, recurring 168-hour workweek. An employee who works 50 hours one week and 30 the next gets 10 overtime hours, even though the biweekly total is exactly 80. Averaging across weeks to avoid overtime is illegal for non-exempt employees.

How do I handle an employee with two different pay rates?

Use the FLSA weighted-average (blended) method: total straight-time earnings from both rates divided by total hours worked gives the regular rate for that week. Overtime hours are then paid at 0.5 times that blended rate on top of the straight-time already paid. Paying overtime only on the lower rate is a common and costly compliance mistake.

What is the difference between semimonthly and biweekly pay?

Biweekly pays every two weeks — 26 checks per year, always the same weekday. Semimonthly pays twice a month on fixed dates (commonly the 15th and last day) — 24 checks per year, each about 8.7% larger for the same salary. Biweekly aligns cleanly with weekly overtime; semimonthly periods split workweeks, so hourly overtime must still be tracked by workweek and trued up.

Do I have to pay for unauthorized overtime?

Yes. If a non-exempt employee works the hours, the FLSA requires you to pay them — including the overtime premium — even if the overtime was not approved. You can discipline the employee for breaking policy, but you cannot withhold the pay.

Which states have daily overtime rules?

A handful of states require overtime by the day, not just the week: California (1.5x after 8 hours/day, 2x after 12), Alaska and Nevada (1.5x after 8, with conditions), and Colorado (1.5x after 12). If you have employees in those states, weekly totals alone are not enough — check each day.

Should payroll hours be tracked in decimals or hours and minutes?

Track punches in real clock time, but compute pay in decimal hours, because pay equals decimal hours times rate. The conversion is minutes divided by 60: 7 hours 40 minutes is 7.67 hours, not 7.40. Most payroll errors we see come from mixing the two formats.

General information based on the FLSA and U.S. DOL guidance. State rules vary. Not legal, tax, or payroll advice.