Last updated July 28, 2026
EPU changes the decimal precision of a single dimension. Pick the dimension, type the number of decimal places you want, and that one dimension is overridden — without touching your dimension style or any other dimension on the drawing.
That is a narrow job, and a genuinely awkward one to do otherwise. Changing precision through the dimension style changes everything using that style; doing it through the properties palette means finding the right field in a long list. This is two picks.
It is by Ade Suharna, dated 4 September 2004, and carries a note that it was later edited by Rick Keller.
This one will not run on AutoCAD LT
Worth stating clearly, because almost everything else in this library will. Most of these routines are plain AutoLISP and stand a reasonable chance on LT 2024 or later, the first releases with AutoLISP support.
This one is different. It reaches the dimension’s precision setting through ActiveX — the object-property interface that lets AutoLISP talk to AutoCAD’s drawing objects as programmable objects rather than as raw entity data. ActiveX is not available on AutoCAD LT at any release, so a routine built on it cannot run there. The give-away is the ActiveX loading call on the second line and the property calls that follow it.
See what runs on AutoCAD LT for the wider picture. On full AutoCAD there is no issue.
What it does in practice
It asks you to select a dimension, reads its current precision, and offers that back as the default in the prompt — so you can see what it is now before deciding what it should be. Type a new number and the override is applied.
Then it asks again. The routine loops, so a run of dimensions that all need the same treatment is a sequence of picks rather than a sequence of commands.
The property it sets is the primary units precision, which is the decimal places on the main measurement. It does not touch alternate units or tolerance precision, which are separate settings.
Command reference
The file defines a single command, EPU — the author’s own abbreviation for edit precision units, spelled out in the first line of the file.
How to load it
Unzip Epu.zip and load epu.lsp with APPLOAD, or add it to the Startup Suite. No support files. Our AutoLISP guide covers loading.
Step-by-step usage
- Type EPU.
- At “Select Dimension.” click the dimension you want to change.
- The prompt shows the current precision in angle brackets. Type the number of decimal places you want.
- It asks for another dimension. Carry on, or escape to finish.
Because the loop has no tidy exit, escaping is how you stop. That is normal for routines of this shape but worth knowing so it does not look like a fault.
Compatibility notes
2004, which makes it one of the newer routines here, and the ActiveX approach it uses is the modern way of doing this kind of work rather than an old one. On full AutoCAD it should be sound. On LT it will not run at all, as covered above.
It applies a dimension override, which is a normal, reversible thing to do — the dimension can be reset to its style later if you change your mind. Even so, try it on a copy the first time so you can see exactly what it changes.
Download
| Name: | EPU |
| Description: | Edit precision units. |
| Type: | AutoCAD AutoLISP Routine |
| Author: | Ade Suharna |
| File Size: | 1 Kb |
| Cost: | Free |
| Worked on: | AutoCAD |
| Download File: | Epu.zip |
Related routines
- DIMROTATE — flip dimensions that read upside down.
- SPER — the other ActiveX routine in this library, with the same LT limitation.
- LLP Suite — a set of dimension checking and fitting commands.