View the total duration of selected clips

Make sure that the Info panel is visible. If it is not, choose Window > Info.
In either the Project panel or Timeline panel, select the clips for which you want to know the total duration. The Info panel displays the number of items selected and the total duration of those items. This information is useful if you want to paste clips into a specific area and need to know the exact duration of the target area or of the source clips.
Note: If you select noncontiguous clips in the Project panel, the Info panel displays the total duration of all the clips you select. However, if you select noncontiguous clips in a sequence, the Info panel displays the duration as a range, from In point of the first clip you selected, to the Out point of the last clip you selected. For the purpose of copying and pasting, the duration of a particular range is more important than the sum of all the clips’ durations. If you copy and paste a noncontiguous group of sequence clips, the pasted clips will occupy the range as noted on the Info panel and the areas that you did not select will be black.