Select Cell for Measurement
To use the take-off tool to calculate the length of an item, first focus on the item in your estimate. The length calculation for the selected item will be displayed at the bottom of the screen.

Your length measurement will be presented in the cell highlighted in yellow. You can also select other cells, such as width and height, to trace additional measurements if needed.
Enable the Length Measurement Tool
Enable the trace toggle in the takeoff toolbar, if it is not already activated.

Click the dropdown on the trace toggle and select “Trace Length” if needed.
Choose the desired line style (colour). You can change the line style later as you trace.
Measuring Lengths
Measuring the Perimeter of an Object: Click on the face of the object to measure its perimeter. This will give you the total perimeter of the selected face:
Measuring Individual Edges: Click on the edge of a face to measure just that edge. This will provide the length of the selected edge:
Combining Measurements: You can continue clicking on additional edges or faces. The total lengths of the selected edges or perimeters of the faces will be summed up in the cell
Removing Measurements: To deselect a measured value, simply click again on an already measured face or edge, and it will be removed from the total.