Time and Percentage Calculations

New Contributor


New to the forum.  Please be gentle...

I am trying to add a factor to the time reported in my timesheets.

The timesheet has duration worked on each task in one column (A), expressed as HH:MM:SS, e.g. 00:19:00.

I would like to create another column (B) that calculates a percentage of that time, which itself is a calculation. So for example, if the percentage calculation was 10%, the result would be 114 seconds, or 00:01:54 expressed as duration, of 00:19:00.

I then want to add column A to column B to get a total.  Thanks.

3 Replies
Of course... As soon as I post something... I have worked it out.


Let's say you have a time such as 00:19:00 in cell A2

If you want the end result in B2, enter the formula




in B2. If you just want the 10% in B2, and the total in C2, enter the formula




in B2, and




in C2. These formulas can be filled or copied down to the rows below.

Thanks@Hans Vogelaar 


The column for the additional 10% is conditional, based on an 'IF' the time in column A is chargeable or not.


Applying =A2*10% then adding to A2 works.