A time duration calculator works out exactly how much time passes between a start time and an end time, in hours and minutes, including a decimal-hours figure for payroll or billing. It handles the one case mental math tends to get wrong: shifts and events that cross midnight, where the end time on the clock is actually earlier than the start time.
Enter a start time and an end time, optionally subtract a break in minutes, and click Calculate Duration. The result shows the duration in hours and minutes, plus the same figure as decimal hours, which is the format most timesheets and billing systems expect.
If the end time you enter is earlier on the clock than the start time, for example 10 PM to 6 AM, the calculator assumes the end time falls on the following day and adds 24 hours before calculating the gap, so overnight shifts come out correct automatically. Any minutes entered in the Subtract Break field are deducted from that raw duration afterward, giving you the actual worked or elapsed time rather than the full clock-to-clock span.
Working out hours and minutes between two times comes up constantly:
If you're totaling hours across several days rather than a single stretch of time, the work hours calculator handles that directly.
If the end time is before the start time, the calculator assumes the end time is the next day — perfect for night shifts or events that span midnight.
Decimal hours express time as a single number — e.g. 7 hours 30 minutes = 7.5 hours. This is useful for payroll and billing calculations.
Enter the total break minutes in the "Subtract Break" field and the calculator deducts that time from the raw duration before showing the final hours and minutes.
Yes — if your end time is earlier in the clock than your start time, such as 10 PM to 6 AM, the calculator automatically adds 24 hours so the result reflects the true overnight duration.
No — the calculator works to the minute, and the decimal hours figure is shown to two decimal places for accurate payroll or billing calculations.
Yes — enter departure and arrival times to see the total travel duration, though you'll need to adjust manually if the trip crosses time zones.