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Calculate hours worked between shift start and shift end times, including overnight work.
Use this work hours calculator to estimate the elapsed length of a shift before breaks, overtime rules, or payroll adjustments are applied. The calculator is designed to give a fast answer, but the quality of the answer still depends on accurate inputs and a clear idea of what decision you are trying to support.
- Enter Shift start and Shift end using the same units you plan to compare or report.
- Read the main estimated shift duration first, then use the supporting outputs to understand the trade-offs behind that result.
- Compare your numbers with the worked examples below if you want a quick reasonableness check.
The breakdown into hours, minutes, and seconds is useful for schedules, while total minutes and total seconds are better when another system needs a single-unit duration. On this page, the primary output is estimated shift duration.
Scenario 1: 09:00 to 17:30 office shift. Inputs used: startTime: 09:00, endTime: 17:30. Example result: 8h 30m 0s. This work shift has an estimated duration of 8h 30m 0s before break deductions. Scenario 2: 19:00 to 03:30 night shift. Inputs used: startTime: 19:00, endTime: 03:30. Example result: 8h 30m 0s. This overnight shift lasts 8h 30m 0s before any unpaid break is removed.
Core formula: duration = end time - start time, with overnight rollover if needed. Times are converted into seconds, and if the end time is earlier than the start time the calculator assumes the period crossed midnight.
- The result is broken into hours, minutes, and seconds.
- Total minutes and total seconds are useful for scheduling and payroll math.
Use this calculator for shifts, appointments, workouts, machine runtimes, and any daily planning that depends on exact start and end times. Related paths for follow-up analysis include hours calculator, time duration calculator, weekly pay calculator, and annual salary calculator.
Most bad outputs come from a few repeated input errors or interpretation mistakes. Use this short checklist before relying on the result.
- Forgetting that an end time earlier than the start is treated as overnight.
- Mixing clock time assumptions when some values are in 12-hour format and others in 24-hour format.
- Using rounded mental math when payroll or scheduling needs exact duration.
