Shift Length Calculator
Calculate the length of a work shift including overnight shifts that cross midnight. Enter values for instant results with step-by-step formulas.
Formula
Net Hours = (End Time - Start Time) - Break Time
The calculator subtracts the start time from the end time to get gross shift duration. For overnight shifts where the end time is before the start time, 24 hours is added. Break minutes are then subtracted to yield net working hours. The result is shown in both hours:minutes and decimal format.
Worked Examples
Example 1: Standard Day Shift
Problem: A worker starts at 8:00 AM and ends at 4:30 PM with a 30-minute lunch break. What is the net working time?
Solution: Start: 8:00 AM = 480 minutes from midnight\nEnd: 4:30 PM = 990 minutes from midnight\nGross time: 990 - 480 = 510 minutes = 8 hours 30 minutes\nBreak: 30 minutes\nNet time: 510 - 30 = 480 minutes = 8 hours 0 minutes\nDecimal: 8.00 hours
Result: Gross: 8h 30m | Net: 8h 00m (8.00 decimal hours) | Day shift
Example 2: Overnight Nursing Shift
Problem: A nurse works from 7:00 PM to 7:30 AM with a 45-minute break. Calculate the shift length and pay at $35/hour.
Solution: Start: 7:00 PM = 1140 minutes\nEnd: 7:30 AM = 450 minutes (next day)\nGross time: (450 + 1440) - 1140 = 750 minutes = 12 hours 30 minutes\nBreak: 45 minutes\nNet time: 750 - 45 = 705 minutes = 11 hours 45 minutes = 11.75 decimal hours\nPay: 11.75 x $35.00 = $411.25
Result: Gross: 12h 30m | Net: 11h 45m (11.75 hrs) | Shift pay: $411.25 | Overnight shift
Frequently Asked Questions
What is the difference between gross and net shift hours?
Gross shift hours represent the total time from your clock-in to your clock-out, including any break time. Net shift hours subtract your break time from the gross total to show your actual working hours. For payroll purposes, most employers pay based on net hours since break time is typically unpaid for non-exempt workers. For example, a shift from 8 AM to 5 PM is 9 gross hours, but with a 60-minute unpaid lunch break, the net working time is 8 hours. The distinction matters for accurate pay calculations.
How does the calculator determine if a shift is a night shift?
The calculator flags a shift as a night shift based on simple time-of-day heuristics. If the start time is at 6 PM or later, if the end time is at 6 AM or earlier, or if the shift crosses midnight (overnight), it is classified as a night shift. This classification is informational and helps you identify whether night shift differentials might apply to your pay. Many employers offer a premium of $1 to $5 per hour for night shift work, though this is not federally mandated and depends on company policy or union contracts.
What is the standard full-time shift length in the United States?
The most common full-time shift in the United States is 8 hours, typically scheduled as five days per week for a total of 40 hours. However, alternative schedules are increasingly popular. Compressed workweeks use four 10-hour shifts, while healthcare often uses three 12-hour shifts. Some industries like firefighting use 24-hour shifts followed by 48 or 72 hours off. The FLSA does not define full-time versus part-time employment, so these designations are set by the employer. Generally, working 30 or more hours per week qualifies as full-time for benefits under the Affordable Care Act.
How do I calculate shift length for a rotating schedule?
For rotating schedules where shift times change weekly or biweekly, calculate each unique shift length separately and then average them over the rotation cycle. For example, a common rotation might include a week of day shifts (7 AM to 3 PM), a week of evening shifts (3 PM to 11 PM), and a week of night shifts (11 PM to 7 AM). Each of these is an 8-hour shift in this example, but if your rotation includes shifts of varying lengths, you can use Shift Length Calculator for each distinct shift and track the pattern to estimate your total monthly and annual working hours.
Is my data stored or sent to a server?
No. All calculations run entirely in your browser using JavaScript. No data you enter is ever transmitted to any server or stored anywhere. Your inputs remain completely private.
Does Shift Length Calculator work offline?
Once the page is loaded, the calculation logic runs entirely in your browser. If you have already opened the page, most calculators will continue to work even if your internet connection is lost, since no server requests are needed for computation.