Choose the mode
Pick "Between two clock times" for a shift or event, or "Sum of several durations" to add tasks.
Calculators
Time Duration Calculator
Free online time duration calculator
Enter the values
Local processingEnter each duration as hours:minutes:seconds, for example 1:30:00 or 00:45.
Result
The result will appear here after you run the tool.
Press Ctrl or Command and Enter to run the tool.
About this tool
About this tool
Time Duration Calculator handles two modes. Between-times mode subtracts two clock times with an optional next-day flag for shifts that cross midnight. Sum mode adds any number of durations entered as hours:minutes:seconds. Both return the total in h:m:s, decimal hours, decimal minutes, and seconds, calculated locally in your browser.
Measure how long something takes in two different ways. Convert the span between two clock times, such as a shift or a class, or add up several durations like tasks in a day. Results appear in hours, minutes, and seconds plus decimal hours and minutes for payroll and planning.
Built for daily work
- Calculate a work shift length including a lunch break.
- Add up study sessions for a weekly total.
- Measure time between two meetings across midnight.
- Convert task durations to decimal hours for a timesheet.
How to use this tool
How to use this tool
Enter the times or durations
For clock times, set start and end and mark the next-day box if the end passes midnight. For sums, add rows in h:m:s format.
Read the result
The total appears in hours, minutes, and seconds with decimal hour and minute equivalents.
Key features
Key features
Two modes in one tool
Between-two-times for shifts and events, and a sum mode for adding up tasks and activities.
Cross-midnight handling
A checkbox marks end times on the next day, so night shifts calculate correctly.
Flexible duration input
Rows accept h:m:s, h:m, or plain minutes, and can be added or removed freely.
Multiple output formats
h:m:s, decimal hours, and decimal minutes cover payroll, logs, and planning needs.
Practical use cases
Practical use cases
- Calculate a work shift length including a lunch break.
- Add up study sessions for a weekly total.
- Measure time between two meetings across midnight.
- Convert task durations to decimal hours for a timesheet.
- Plan a playlist or video sequence total length.
Private by default
For local tools, input is processed in your browser and is not sent to application analytics.
Data processing noticeTechnical details
Technical details
ProcessingLocal browser processing
ModesBetween two times and sum of durations
Outputh:m:s, decimal hours, decimal minutes, seconds
MidnightNext-day flag for overnight spans
Limitations and important notes
Limitations and important notes
- Clock time mode uses hours and minutes, not seconds.
- Durations are capped at sensible day scale; enormous inputs round for display.
- The tool adds durations, it does not schedule or timezone-adjust events.
Frequently asked questions
Frequently asked questions
When the end time is on the next day, tick the checkbox and 24 hours are added to the calculation, so 23:00 to 01:00 becomes 2 hours.
Hours:minutes:seconds like 1:30:00, hours:minutes like 2:15, or plain minutes like 90.
Different contexts need different formats. Payroll often uses decimal hours, while logs use h:m:s, so both are provided.
Clock time inputs use hours and minutes, which covers most shift and event cases. The sum mode accepts seconds.
Related guides and solutions
Related guides and solutions
What local browser processing means for online tools
A transparent explanation of local tool processing, temporary browser memory, local storage, downloads, analytics boundaries, and cases that require remote services.
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