Help - Scale branch lengths
TreeGraph allows to calculate the distance per branch length unit so that the tree has a certain width. This option is only available if all branch lengths in the current document are specified. (Only the root branch length can be missing if the tree is shown unrooted.) Alternatively you could directly specify the distance per branch length units in the document formats-dialog.
If you import Newick or Nexus files the distance per branch lengths unit is automatically set so that the tree has a width of 15 centimeters.
You can access the Scale branch lengths-dialog by selecting "Scale branch lengths" from the format menu. In the dialog you can specify the length of the path from the root node to terminal which has the maximal distance to the root in millimeters or points. This equivalent to the width of the tree not including terminal node names, legends and document margin. When you click OK the distance per branch length unit is calculated in the following way:
DistancePerBranchLengthUnit = SpecifiedLength / LengthOfTheLongestPath
DistancePerBranchLengthUnit] = mm / branch length units
SpecifiedLength] = mm
LengthOfTheLongestPath] = branch length units