A warehouse supervisor logs five eight-hour shifts, hands the sheet to payroll, and expects 40 hours of straight time. Payroll comes back with 37.5 because each shift included a 30-minute unpaid lunch the supervisor forgot to subtract. The check is short by half a day’s pay — not because anyone cheated, but because “hours worked” and “hours on site” are not the same number. An overtime calculator that separates gross shift time from net paid time, then layers daily and weekly overtime thresholds on top, turns a confusing spreadsheet into one clear total.
Enter your shifts, set break durations and overtime rules, and the result splits into regular hours, overtime hours, and a pay estimate you can cross-check against a stub.
Gross Hours vs Net Hours: Where the Paycheck Disagreement Starts
Clock-in to clock-out is gross time. Subtract unpaid breaks and you get net work hours — the figure that actually hits your pay stub. A 9-to-5 with a 30-minute lunch is 8 gross hours but only 7.5 net. Over five days that gap is 2.5 hours, which at $25/hour means more than $60 missing from the check if someone forgets the deduction.
Rounding makes things trickier. If your employer rounds to the nearest 15 minutes, clocking in at 8:53 counts as 9:00 and clocking out at 5:07 counts as 5:00. That shave on each end chips a quarter-hour off the day. The calculator lets you toggle rounding modes (none, nearest 5, nearest 15) so the total matches your workplace rule.
Daily Overtime, Weekly Overtime, and Why the Order Matters
Federal FLSA rules trigger overtime after 40 hours in a workweek. Some states — California is the big one — also trigger it after 8 hours in a single day, and double time after 12. When both rules apply, daily overtime is calculated first. Hours already flagged as daily OT do not count toward the 40-hour weekly cap, so applying them in the wrong order skews the overtime bucket.
The tool lets you set a weekly threshold, an optional daily threshold, and an optional double-time threshold. If your state does not have a daily rule, leave it blank and the calculator only checks the weekly cap. If you work four 10-hour shifts in a state with an 8-hour daily limit, each day generates 2 hours of daily OT even though the week total is only 40.
Cross-Midnight Shifts and the Week-Start Trap
Night-shift workers who clock in at 10 PM and out at 6 AM create an overnight span. The calculator assigns the whole shift to the start date, keeping weekly grouping clean. But which day starts the workweek can shift overtime totals by hours. A Sunday-start and a Monday-start week produce different weekly OT when a long shift straddles the boundary. The tool defaults to Sunday but you can switch to Monday or Saturday.
If your pay stub disagrees with the calculator, check the week-start setting first. Then check whether your employer rounds before or after the break deduction — this tool rounds first, then subtracts breaks, which matches the more common payroll-software convention.
Payroll Questions
- How do I calculate overtime hours for the week? Enter each shift’s start/end time and break minutes, set the weekly threshold (usually 40), and the calculator flags every hour beyond that cap as OT at 1.5× your rate.
- Are unpaid breaks subtracted automatically? You enter break minutes per shift. The tool subtracts them from gross time before applying overtime rules.
- Does the pay estimate cover double time? Yes. If you set a double-time threshold (often 12 hours/day), hours beyond it calculate at 2× your hourly rate.
- What if I work overnight? Enter the start time on day one and the end time the next morning. The calculator detects the cross-midnight span and counts the hours correctly.
Related tools: Time Card Calculator for multi-punch time cards with auto-deduct breaks, Business Days Calculator for working-day counts between two dates, Days Between Dates Calculator for raw calendar-day spans, and How Long Since / Until for elapsed time with hours and minutes.
Overtime thresholds and multipliers are user-entered — this tool does not enforce any specific jurisdiction’s labor law. Verify rules with your employer or HR department before relying on the figures for payroll.