Pick a start time and an end time, add an unpaid break if you had one, and see the exact duration in hours and minutes and in decimal hours. Shifts that run past midnight are handled for you.
Runs in your browser. Nothing you type is sent anywhere.
This time duration calculator is for workers, students, parents and anyone who needs to know how long something lasted between two clock times. You get the result in hours and minutes, in decimal hours for timesheets, and in total minutes. If the end time is earlier than the start time, the tool treats it as an overnight span.
How Do You Calculate Time Duration Between Two Times?
Turn both times into minutes after midnight, subtract the start from the end, then subtract any break. If the end is earlier than the start, add 1,440 minutes for crossing midnight. For example, 9:00 AM to 5:30 PM is 510 minutes, and minus a 30 minute break gives 480 minutes, which is 8 hours or 8.00 decimal hours.
What Is the Formula for Time Duration?
Duration equals end time minus start time, with both written as minutes after midnight, minus any break.
duration = end − start (add 1,440 if end is earlier than start) − break
decimal hours = duration ÷ 60
The tool reads times on the 24-hour clock, where 17:30 means 5:30 PM, the same way the ISO 8601 standard writes times. A day has 1,440 minutes (24 × 60), so adding 1,440 is how the maths steps across midnight. Decimal hours show minutes as a fraction of an hour, so 7 hours 15 minutes becomes 7.25, which is what most payroll systems use.
How Do You Calculate an Overnight Shift That Crosses Midnight?
You add 24 hours to the end time before you subtract, because the shift finishes on the next calendar day. A night shift from 22:30 to 06:15 is 06:15 + 24:00 = 30:15, minus 22:30, which is 7 hours 45 minutes. Take off a 30 minute meal break and the paid time is 7 hours 15 minutes. This tool does this step for you whenever the end time is earlier than the start time.
Should a Break Be Taken Off Worked Hours?
It depends on the length of the break and the law where you work. Under the US Fair Labor Standards Act, the Department of Labor says short rest breaks of about 5 to 20 minutes count as paid work time, while a bona fide meal period of usually 30 minutes or more, where you are fully relieved of duty, is not work time. So only enter unpaid breaks in the break box. Other countries have their own rules, so check your contract.
Common Shift Durations
These results come straight from this tool:
| Start to end | Break | Duration | Decimal |
|---|---|---|---|
| 09:00 to 17:00 | 30 min | 7 h 30 min | 7.50 |
| 09:00 to 17:30 | 30 min | 8 h 0 min | 8.00 |
| 08:00 to 16:30 | 30 min | 8 h 0 min | 8.00 |
| 06:00 to 14:00 | 15 min | 7 h 45 min | 7.75 |
| 07:00 to 19:00 | 60 min | 11 h 0 min | 11.00 |
| 22:00 to 06:00 | none | 8 h 0 min | 8.00 |
| 22:30 to 06:15 | 30 min | 7 h 15 min | 7.25 |
To add up several days of shifts into a weekly total, use the time card calculator. If your rota is written in 24-hour style and you want it in AM and PM, the military time converter switches between the two.
Worked Example
A nurse works a night shift from 22:30 to 06:15 with a 30 minute unpaid meal break. Enter 22:30 as the start, 06:15 as the end and 30 as the break. The tool spots that the shift ends the next day and shows 7 hours 15 minutes, or 7.25 decimal hours and 435 minutes. Before the break the span was 7:45. At $30 an hour that shift pays 7.25 × $30 = $217.50. For a day shift from 9:00 to 17:30 with the same break, the answer is 8 hours, the same figure the hours calculator gives for a single span.
How Do You Use the Time Duration Calculator?
Enter the start time
Type or pick the time you started in the Start time box.
Enter the end time
Pick the finish time. If it is earlier than the start, the tool counts it as the next day.
Add your break
Type unpaid break minutes, or leave it at 0 if you had no break.
Read the duration
See hours and minutes, decimal hours, total minutes and the span before the break.
Frequently Asked Questions
How many hours is 9 AM to 5 PM?
9 AM to 5 PM is 8 hours, or 480 minutes. If you take a 30 minute unpaid lunch break, the paid time drops to 7 hours 30 minutes, which is 7.5 decimal hours on a timesheet.
How many hours is 7 AM to 7 PM?
7 AM to 7 PM is 12 hours. With a one hour unpaid break the worked time is 11 hours, or 660 minutes. This is a common pattern for 12 hour hospital and warehouse shifts.
How do I write 7 hours 45 minutes in decimal hours?
7 hours 45 minutes is 7.75 decimal hours. Divide the 45 minutes by 60 to get 0.75, then add it to the 7 whole hours. Payroll multiplies 7.75 by the hourly rate.
What happens if I enter the same start and end time?
The tool shows a message instead of a result, because the same time could mean zero minutes or a full 24 hours. For a full day, split it into two spans, such as 08:00 to 20:00 and 20:00 to 08:00.
Can the break be longer than the shift?
No. If the break is equal to or longer than the time between start and end, the tool shows an error. For example, a 90 minute break inside a one hour span from 12:00 to 13:00 is not possible.
Does this tool handle daylight saving time changes?
No. It assumes every day has 24 hours. On the night clocks go forward, a shift really lasts one hour less, and on the night they go back it lasts one hour more, so adjust by hand.
Sources and Further Reading
Related Tools
Last reviewed: October 2026