How this calculator works
Each row is one span of time with a whole-hour part and a minute part. Both are converted to seconds and added across the visible rows, so the running total never needs manual carrying. The same total is then shown in decimal hours and in minutes, which is what many timesheets expect.
Formula
seconds = 3600 x hours + 60 x minutes for each row. Total = sum of the row seconds. Total hours = total / 3600. Total minutes = total / 60. The clock text is whole hours, then floor((total mod 3600)/60) minutes and the remaining seconds.
Worked example
Row 1 at 1 hour 30 minutes and row 2 at 2 hours 45 minutes total 4:15:00. That is 4.25 decimal hours or 255 minutes. The running-total column shows 1:30:00 for row 1 and 4:15:00 after row 2.
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Frequently asked questions
Why can minutes go no higher than 59?
A row is a normal clock-style span, so 75 minutes should be written as 1 hour 15 minutes. Rejecting the out-of-range value prevents a silent carry that could hide a typing mistake.
Can I add more than six rows?
The page offers six rows, which covers a typical week of shifts or a set of meeting lengths. For a longer list, combine blocks: add six rows, then add that result as the first row of the next block.
Does this handle overnight spans?
It adds durations, not clock readings. A shift from 22:00 to 06:00 is 8 hours of duration here; the page does not need to know which date each reading belongs to.