Elapsed time cell format

Format the cell with the custom number format [h]:mm:ss so elapsed hours continue beyond 24 instead of resetting to zero.

Apply the format in Excel for Windows

1. Select the cell or range containing the elapsed time.
2. Press Ctrl+1 to open Format Cells.
3. Select Number → Custom.
4. In Type, enter one of these formats:
   • [h]:mm:ss — total hours, minutes, and seconds, such as 27:15:30
   • [h]:mm — total hours and minutes, such as 27:15
   • [mm]:ss — total elapsed minutes and seconds
   • [ss] — total elapsed seconds
5. Select OK.

The square brackets tell Excel to display the accumulated total rather than treating the result as a time of day. Microsoft documents [h]:mm for elapsed hours and [mm]:ss for elapsed minutes.^1^

For example, if A2 is the start time and B2 is the end time, use:

=B2-A2

Then apply [h]:mm:ss to the result cell.

If changing the format has no effect, the source values may be stored as text rather than valid Excel times. Formatting changes only how a numeric value is displayed; it does not convert text into a time value.

References

1. Format numbers as dates or times