Time Duration Calculator
Duration = end time - start time - break time. If the end time is earlier, the range is treated as overnight.
Enter start, end, and break time
Enter the start time and end time. If the range crosses midnight, choose the overnight option or enter the dates as well when the tool supports dates.
Use this for elapsed time, class time, shift length, travel windows and event durations. Add breaks only when you want net time instead of total time.
Before using the result, check whether you need readable time, total minutes or decimal hours. Each format fits a different task.
Reading elapsed time
The result shows how much time passed between the two entries. It may show hours and minutes, total minutes and decimal hours. These formats describe the same duration in different ways.
For example, 1 hour 30 minutes is 90 minutes or 1.5 decimal hours. The best format depends on whether you are reading it, entering payroll or doing more math.
Duration formula
The calculator converts each time to minutes after midnight. For same day ranges, it subtracts start minutes from end minutes. For overnight ranges, it adds 24 hours before subtracting.
If breaks are included, break minutes are subtracted after the gross duration is found. That keeps the overnight logic separate from the net time adjustment.
This minute based method avoids AM and PM guessing. It also makes it easier to compare the result with a spreadsheet or time card.
A shift with a lunch break
From 9:15 AM to 2:45 PM, the elapsed time is 5 hours and 30 minutes. In decimal hours, that is 5.5 hours.
From 10:30 PM to 6:15 AM, the range crosses midnight. Count 1 hour 30 minutes to midnight, then 6 hours 15 minutes after midnight. The total is 7 hours 45 minutes.
If you also had a 30 minute unpaid break, subtract it after the overnight total is found. The net time would be 7 hours 15 minutes.
Overnight times and unpaid breaks
The biggest mistake is treating an overnight end time as earlier on the same day. That creates a negative result unless the calculator knows the range crosses midnight.
Another common mistake is mixing decimal time with hour and minute time. 1.30 hours is not 1 hour 30 minutes. It is 1 hour and 18 minutes.
Time Duration Calculator FAQ
How do I calculate time between two times?
Convert each time to minutes after midnight, subtract the start from the end, then convert the result back to hours and minutes.
The calculator does that for you. It is especially helpful when the start and end times use AM and PM or when the duration crosses midnight.
How do I calculate a duration that goes past midnight?
Treat the end time as being on the next day. One simple method is to count from the start time to midnight, then add the time from midnight to the end time.
For example, 11:00 PM to 2:30 AM is 1 hour to midnight plus 2 hours 30 minutes, or 3 hours 30 minutes.
Should break time be included in the result?
Include breaks when you want total time on the clock or total elapsed time. Subtract breaks when you want net working time.
For work records, use the rule your workplace uses. Some records show gross shift length and break time separately.
If you are unsure, keep both values. Gross duration and net duration answer different questions, and both can be useful.
What is the difference between 1.5 hours and 1:50?
1.5 hours means 1 hour and 30 minutes because half an hour is 30 minutes. 1:50 means 1 hour and 50 minutes.
This is a common source of payroll and spreadsheet mistakes. Convert minutes by dividing by 60 when you need decimal hours.
Why did I get a negative duration?
The end time may be earlier than the start time because the range crosses midnight. Turn on overnight calculation or include the correct dates.
Also check AM and PM. Typing 7:00 AM instead of 7:00 PM changes the result by 12 hours.
A negative result is usually a setup clue. It tells you the calculator understood the end time as earlier on the same day.