- The Units Setting (Drawing Units)
- The DWG Units Setting (-DWGUNITS)
The term "units" is an oft-used one in AutoCAD-speak, and can mean different things. Here's a brief overview.
The Units Setting (Drawing Units)
The Units setting (aka Drawing Units) makes it easy to set what you'll be drafting in your plan. The Drawing Units you set will be used in measurements of length and area in your drawing.
The Drawing Units dialog box shows the units you currently have set in your drawing. You can open this dialog box by typing UNITS in the Command line and pressing Enter.
Under Length, you can see the type and precision of units that are currently set. The menu under Insertion Scale shows whether objects in your drawing will be measured in feet, inches, meters, etc.
In this example, the drawing is set to Decimal Feet at a precision of 0.0000 – for example, 10.5000 feet.
Of course, the quickest and easiest way to set your drawing units is to use our Scale tool.
This tool opens our Plot Scale dialog box, where you can easily set your drawing units to architectural inches, decimal feet, meters, millimeters, or centimeters while also setting your scale.
Regardless of which tool you use, it's extremely important that you set your units and scale before you start working on a drawing.
AutoCAD is considered "unitless" by design. The definition of a line in AutoCAD is always something like "0,0 – 10,10." In this case, the line is extending from the coordinates 0,0 to the coordinates 10,10. Note there is no Unit specified – just the numeric coordinates. So no matter what you change the units of the drawing to be, the line will still extend from 0,0 to 10,10. So the term "unitless" is misleading; it's very much hard set to a unit type. What does this mean for you as the designer? You need to be extremely diligent in confirming the units.
Verifying Your Units Setting
You can easily verify that your units are set correctly in an existing drawing by drawing and measuring a polyline. How to verify your units
DWG Units (-DWGUNITS)
The DWG Units (-DWGUNITS) setting determines how objects are inserted and scaled into your drawing. This setting should definitely match your drawing units setting. If not, objects such as your blocks will scale incorrectly when placed.
Certain ACAD 2007 proxies can change these settings – one of many reasons it's incredibly important to follow our steps to clean your drawings and Xrefs.
If your DWG Units setting is off – which happens somewhat rarely – you can fix it by following these steps.