Time Duration Calculator
Our work hours calculator with breaks adds your shifts, subtracts unpaid breaks and handles overnight hours for accurate totals.
Formula & worked example
Formula: Net minutes = (end − start, +24 h if the end is earlier) − unpaid break. Decimal hours = net minutes ÷ 60.
Example: 22:00 to 06:30 with a 30-minute break = 8 h 30 m − 30 m = 8 h 00 m = 8.00 decimal hours.
Method & source: 24-hour clock arithmetic with a midnight rollover for overnight shifts. See how we test our calculators.
Next step: try overtime pay or business days in a pay period or freelance hourly rate.
Work Hours, Breaks and Overnight Shifts
A time duration calculator measures the time between a start and an end time. Used as a work hours calculator with breaks, it also subtracts unpaid breaks so you see only the hours you actually worked.
It is built for real shifts: a night shift that starts at 10 pm and finishes at 6 am is handled correctly, and you can add several shifts to total a whole week.
Turning Clock Times Into Total Hours
Add one row per shift with a start time, an end time and the unpaid break in minutes. The calculator does the rest.
- Overnight shifts: If the end time is earlier than the start time, the shift rolls over past midnight.
- Unpaid breaks: Break minutes are subtracted from the shift length.
- Multiple shifts: Add as many rows as you need and get a running total.
- Decimal hours: Totals shown as hours and minutes and as decimals for timesheets.
- Optional pay: Enter an hourly rate to see estimated earnings.
Times are read on a 24-hour clock in the input fields, and results are displayed both ways so they are easy to copy into payroll or invoices.
Why Tracking Work Hours Matters
Accurate hours mean accurate pay. Small mistakes with breaks or midnight rollovers add up quickly across a month.
- Fill in timesheets and invoices with hours you can defend.
- Check payslips against the time you actually worked.
- Plan shift patterns and overtime for a team.
- Bill clients by the hour without rounding errors.
- Compare planned hours with real hours over a week.
A work hours calculator with breaks turns start and finish times into a clear, payable total in seconds.
Worked walkthrough: a night shift
A nurse works from 7:30 pm to 7:30 am with a 45-minute unpaid break. Because the end time is earlier than the start time, the calculator treats the shift as running past midnight: 12 hours gross, minus 45 minutes, gives 11 hours 15 minutes, or 11.25 decimal hours. Adding three more identical shifts makes four shifts and 45.00 decimal hours in total. At an hourly rate of 30, that is an estimated 1,350 before tax and overtime rules. Decimal hours are what most payroll and invoicing systems ask for.
Practical tips for Time Duration calculations
- Enter times in the format your device shows; the tool reads them as a 24-hour clock internally, so 7:30 pm and 19:30 are the same.
- Only unpaid breaks should be entered. Paid breaks are part of your working time and should be left out of the break box.
- If a shift is exactly 24 hours, split it into two rows – identical start and end times are read as zero minutes.
- Round decimal hours only at the very end, on the weekly total, to avoid small rounding differences building up.
- Overtime premiums and night differentials vary by employer and country. Use this tool for the hours and apply your own pay rules afterwards.
How hours between two times are calculated
The calculator works on the 24-hour clock. Net hours are the time from start to end, minus any unpaid break. A shift from 09:00 to 17:30 with a 30-minute unpaid break is 8 hours 30 minutes gross and 8 hours 00 minutes net. If the end time is earlier than the start time, the shift is treated as running past midnight, so 22:00 to 06:00 is 8 hours.
A shift that starts and ends at exactly the same time is read as zero hours rather than 24, so split a full-day shift into two entries.
Paid and unpaid breaks
Only unpaid breaks should be subtracted. A paid tea break stays in the working time. Whether a break must be given at all depends on the country and the contract: in the UK, for example, workers are generally entitled to a 20-minute rest break when they work more than six hours, while US federal law does not require meal breaks and state rules vary. Enter the breaks your employer actually deducts.
Minutes as decimal hours
Payroll and invoices usually need decimal hours, because 7 hours 30 minutes cannot be multiplied by a rate directly. Divide the minutes by 60.
| Minutes | Decimal hours |
|---|---|
| 10 | 0.17 |
| 15 | 0.25 |
| 20 | 0.33 |
| 30 | 0.50 |
| 45 | 0.75 |
Round only at the end. Rounding each entry to two decimals before adding can leave the weekly total a few minutes out.
A weekly timesheet example
Add one entry per shift. Monday 09:00–17:30 with a 30-minute break gives 8h 00m, Tuesday 08:30–16:45 with a 45-minute break gives 7h 30m, Wednesday 07:15–15:00 with a 30-minute break gives 7h 15m, and a Thursday night shift 22:00–06:00 with no break gives 8h 00m. The week totals 30 hours 45 minutes, which is 30.75 decimal hours. Enter an hourly rate to see the pay for the same total.
From hours to pay
Extra hours are often paid at a higher rate, and the rules differ by employer and country. Once you have your total, the overtime pay calculator applies time-and-a-half or double time, and the hourly to salary calculator shows what an hourly rate is worth over a year. For counting whole working days instead of hours, use the business days calculator.
Frequently Asked Questions (FAQs)
Enter the start time, end time and unpaid break in minutes. The calculator subtracts the break from the total shift length to give your net working hours.
Yes. When the end time is earlier than the start time, the calculator assumes the shift finishes the next day, so 22:00 to 06:00 is 8 hours before breaks.
Yes. Use “Add shift” to create more rows – for example one per day of the week – and the total updates for all of them.
Divide the minutes by 60 and add them to the hours. 7 hours 30 minutes is 7.5 hours. The calculator shows this decimal figure automatically.
If you enter an hourly rate, pay is the net decimal hours multiplied by that rate. Taxes and overtime premiums are not included.
Enter the start and end time. The calculator returns the duration in hours and minutes and as decimal hours, and it handles times that cross midnight.
Type 30 in the Unpaid break field for that shift, and the calculator takes it off the time between the start and end. For example, a shift from 09:00 to 17:30 is 8 hours 30 minutes long; minus a 30-minute break that leaves 8h 00m, or 8.00 decimal hours. Each shift row has its own break field.
Add one row per shift. The calculator adds every shift, minus breaks, into a weekly total in hours and minutes and in decimal hours for payroll.
Confirm official deadlines. Results follow the calendar rules described on this page. Contracts, court time limits and official deadlines can count days differently, so confirm any legally important date against the governing document. See our full disclaimer.