The complete source code for TLEN.LSP is widely available. You can copy it from a trusted source, such as a verified GitHub Gist. The core code is as follows:
The humble tlen.lsp is a testament to the power and flexibility of AutoLISP. For years, it has provided a quick and free solution for summing lengths in AutoCAD. While the original script can sometimes falter in modern versions, the path to making it work is well-understood. By following the loading and troubleshooting steps in this guide, you can keep this classic tool in your workflow.
Check your command line. The script will output a message similar to: Total length of selected objects: 1452.84 autocad tlenlsp download work
How to Download, Install, and Work with the AutoCAD TLEN.lsp Routine
Calculating the total length of multiple lines, polylines, arcs, and circles is a frequent requirement in CAD drafting—whether for calculating cable lengths, piping, fencing, or material take-offs. AutoCAD doesn't have a native, single-click command to sum the lengths of complex, disjointed selections. The complete source code for TLEN
For users who want to learn more about using LISP in AutoCAD, I recommend:
For advanced workflows, modify the ssget line to select only objects on specific layers. For instance, change: For years, it has provided a quick and
Some custom versions of TLEN use a different command name. If TLEN does not work after loading, look at the command line feedback. The message might say C:LL or something similar—that is the actual command name you need to type.