Revit tutorial - Dividing lines equally 

In this Revit tutorial, we will take a closer look at Dividing Lines Equally
To divide a line into equal segments
Draw or pick a line.
On the Toolbar, click the Split icon.
Split the line into the number of segments required (they do not need to be equally spaced at this point).
On the Basics or Drafting tab of the Design bar, click the Dimension tool.
On the Options bar, click the Linear button for dimensioning.
Select the end points of the segments and create the dimensions.
Click the Toggle Dimension Equality (the EQ control at the top of the dimensions) to activate it.
The segments should now be equally spaced. You will have the option to delete the dimensions or retain them. If you delete the dimensions, a warning dialog box will be displayed. Click OK to leave the elements constrained (if you change the length of one segment, the other segments will have the same length) or click Unconstrain to remove the constraints.