Toolvantas

Everyday calculator

Time Duration Calculator

Use this free time duration calculator to compute shift hours, decimal payroll hours, and break deductions between two times or sum HH:MM:SS durations.

Choose time calculation mode

If end time is earlier, overnight midnight rollover is applied.
For multi-day trips or events.
Subtracted from gross elapsed time.

Calculated duration

Net duration after 30 min break

8h 00m 00s
Decimal hours (payroll)8.00 hrs
HH:MM:SS format08:00:00
Total minutes480 min
Gross pay / Seconds28,800 sec

Breakdown

    Standard hours/minutes vs. payroll decimal hours

    Payroll and invoicing software requires decimal hours rather than colon-separated minutes. Mixing the two is a costly timesheet mistake:

    • 8 hours 15 minutes = 8 + (15 ÷ 60) = 8.25 hours (not 8.15).
    • 8 hours 30 minutes = 8.50 hours (not 8.30).
    • 8 hours 45 minutes = 8.75 hours (not 8.45).
    • Always copy the Decimal hours (payroll) tile when multiplying hours by an hourly billing rate.

    Overnight shifts & video/audio timeline sums

    • Night shifts across midnight: If you start at 22:00 (10:00 PM) and finish at 06:30 (6:30 AM), the calculator automatically rolls across midnight to compute 8h 30m gross time.
    • Media & race splits: Switch to Add / subtract durations to total multiple HH:MM:SS segments for YouTube chapters, podcast edits, aviation logs, or marathon splits.

    Frequently asked questions

    How do I convert hours and minutes to decimal hours?

    Keep the whole hours, divide the minutes by 60, and divide any seconds by 3,600. For example, 7 hours 45 minutes = 7 + (45 ÷ 60) = 7.75 decimal hours.

    How does the calculator handle overnight shifts past midnight?

    Whenever the End time is earlier on the clock than the Start time (such as 11:00 PM to 7:00 AM), the calculator automatically treats the End time as occurring on the next calendar day.

    What if my break deduction is longer than the shift?

    The calculator flags an alert whenever the unpaid break exceeds total elapsed time so negative payroll hours cannot slip through unnoticed.

    Can I enter more than 60 minutes in "Add / subtract durations"?

    Yes. Entering 90 minutes in a row automatically carries into 1 hour 30 minutes without error.

    Does Clock time +/− duration show both 12-hour AM/PM and 24-hour formats?

    Yes. The primary output displays 12-hour AM/PM clock time while the breakdown tiles show 24-hour military time and exact day rollover (+1 day, −1 day).

    Are my timesheet entries saved externally?

    No. All calculations execute locally inside your browser tab.

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