TreeMat is a program which evaluates an additive distance matrix starting from a tree.

Enter your tree in Newick format used by Phylip etc.
Such data is generated by programs like Neighbor and Fitch (parts of Phylip).

(((Bovine:0.9119, Mouse:0.7747):0.4122, (Gibbon:0.3943, (Orang:0.2918, (Chimp:0.1471, Human:0.1221):0.0673):0.0255):0.0014):0.2002, Gorilla:0.0000);