Course summary: Add or subtract time

Suppose that you want to know how many hours and minutes it will take to complete two tasks. You estimate that the first task will take 6 hours and 45 minutes and the second task will take 9 hours and 30 minutes.

1. In cell B2 type 6:45, and in cell B3 type 9:30.

2. Type =B2+B3 in cell B4, and then press Enter.

It will take 16 hours and 15 minutes to complete the two tasks.

You can also add up times by using AutoSum to sum numbers. Click in cell B4. Then on the Hometab, click AutoSum. The formula will look like this: =SUM(B2:B3). Press Enter to get the result, 16 hours and 15 minutes.

Subtract time

You know your start and end times at a volunteer project, and want to know the elapsed time.

1. In cell B2 type the start time, enter a space, and then type “a” for AM or “p” for PM, and press Enter. In cell C2, type the end time, including “a” or “p” as appropriate, and press Enter. Type the other start and end times for your friends Joy and Leslie.

2. In cell D2, subtract the end time from the start time by typing the formula: =C2-B2, and then pressing Enter.
We need to format cell D2 to get rid of “AM.”

3. Then on the Hometab, click Format> Format Cells.

4. In the Format Cellsbox, click Customin the Categorylist.

5. In the Type list, click h:mm(for hours and minutes), and then click OK. Now we see that Richard worked 3 hours and 45 minutes.

6. To get the results for Joy and Leslie, copy the formula by clicking in cell D2 and dragging to cell D4. The formatting in cell D2 is copied along with the formula.