Decimal hours
Decimal hours express minutes as a fraction of 60. Thirty minutes is 0.5 hour, 15 minutes is 0.25 hour, and 45 minutes is 0.75 hour.
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Calculator
Time Duration Calculator
Calculate elapsed time between clocks or full date-and-time values. Subtract breaks, handle overnight shifts, convert the result to decimal hours, and total repeated periods.
🔒 100% private browser calculations
Your dates, times, breaks, and totals stay on your device. Xepoca performs every duration calculation locally and does not upload or store what you enter.
Calculate a duration
Use clock times for shifts and sessions, or choose exact dates for longer spans.
Time settings
Enter the interval, break, rounding preference, and optional repeat count.
Break to subtract
Duration results
See the elapsed, net, rounded, repeated, and decimal totals at a glance.
Total duration
7h 30m
7.5 decimal hours · 450 minutes
Elapsed
8h 0m
Break
30m
Net duration
7h 30m
Rounded period
7h 30m
Repeat count
1×
Rounding change
No change
Elapsed-time composition
Break versus usable duration before rounding.
Net 93.75%Break 6.25%
Decimal hours
7.5
Total minutes
450
Total seconds
27,000
24-hour days
0.3125
Calculation breakdown
The break is subtracted first, optional rounding is applied second, and repeat count is applied last.
Raw elapsed duration8h 0m 0s
Break subtracted30m 0s
Net duration7h 30m 0s
Rounding ruleNo rounding
Rounded duration7h 30m 0s
Final total7h 30m 0s
How to calculate time duration
A time duration is the elapsed interval between a starting point and an ending point. For clock times on the same day, subtract the start from the end. If a shift crosses midnight, carry the end time into the following day before subtracting.
Breaks are normally removed after finding the raw elapsed duration. For example, a 9:00 AM to 5:00 PM interval is eight hours. Subtracting a 30-minute break leaves a net duration of 7 hours 30 minutes, or 7.5 decimal hours.
Date & time mode uses the calendar values exactly as entered and calculates a wall-clock span without applying timezone or daylight-saving adjustments. Use a timezone-aware tool when you need to compare instants across different zones.
Duration formats and common uses
Overnight shifts
In Time only mode, an earlier end time can be treated as the following day. A 10:00 PM to 6:00 AM shift is therefore eight hours before breaks.
Repeated periods
Use repeat count when the same net duration occurs multiple times, such as five identical workdays, sessions, machine runs, or study blocks.
Rounding
Optional nearest-interval rounding is useful for estimates and timekeeping workflows, but the calculator does not determine which rounding policy is appropriate or legally permitted.
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Frequently Asked Questions
Is the Time Duration Calculator free?+
Yes. You can calculate clock durations, date-and-time spans, breaks, rounding, repeated periods, and decimal hours without creating an account.
Can it calculate an overnight shift?+
Yes. In Time only mode, keep overnight handling enabled. If the end time is earlier than the start time, the calculator treats the end as occurring on the following day.
How do I subtract a lunch or rest break?+
Enter the break in hours and minutes. The calculator subtracts that break from the raw elapsed duration before optional rounding and repeat-count multiplication.
How are decimal hours calculated?+
The final duration in seconds is divided by 3,600. For example, 7 hours 30 minutes equals 7.5 decimal hours.
Does date mode account for daylight-saving changes?+
No. Date & time mode measures the wall-clock values exactly as entered and does not apply timezone or daylight-saving transitions.
What happens when start and end times are equal?+
Equal clock times produce a zero duration. The calculator does not assume a full 24-hour interval unless you enter explicit dates that are one day apart.
Should I round work hours?+
Only if rounding is appropriate for your workflow and permitted by the policy or rules that apply to you. Xepoca provides the math but does not determine employment, payroll, or legal requirements.
Are my dates and times uploaded?+
No. All calculations run locally in your browser and the values you enter are not uploaded by this tool.