AutoCAD

How To Change Length Unit In AutoCAD?

Understanding Units in AutoCAD

Changing the length units in AutoCAD is an essential step for ensuring accurate measurements in your drawings. The software supports various unit types, allowing users to work in scenarios that best fit their project needs. Whether you’re switching from inches to millimeters or redefining the unit format altogether, knowing the right process is vital.

Steps to Change Length Units in AutoCAD

1. **Start a New Drawing**: Initiate AutoCAD and create a new drawing file to work in a clean environment.

  1. Access the Command Line: Type UNITS into the command line and hit Enter. This command will open the Drawing Units dialog box.

  2. Select Your Unit Type: From the dialog box, you’ll see various unit types such as architectural, decimal, fractional, and metric. Choose the unit you need based on your project requirements.

  3. Setting the Drawing Scale: After selecting your desired unit, it is crucial to adjust the drawing scale. This can be necessary, especially if you’re importing or working with existing files. If adjusting from inches to millimeters, remember that one inch equals 25.4 mm.

  4. Finalizing Settings: Once you’ve selected the appropriate units and set the scale properly, ensure that any options or settings are saved. You may want to check the “Save as Default” option if you want these settings to apply to future drawings.

Changing Units from Inches to Millimeters

1. **Open the Dimension Style Manager**: Use the `DIMSTY` command to access the Dimension Style settings.

  1. Create a New Style: In the Dimension Style Manager, click on “New” to set up a new dimension style dedicated to millimeters.

  2. Configure the Primary Units: On the Primary Units tab, input “mm” in the Suffix box. Adjust the Scale Factor to 25.4 to convert from inches to millimeters accurately.

  3. Apply Changes: Press OK to save your new dimension style, ensuring that all dimensions in your drawing now reflect the millimeter measurements.

Adjusting Units to Centimeters

1. **Initiate Object Scaling**: Click on the Modify panel under the Home tab and select the Scale option.

  1. Select Objects: At the command prompt, use the “select all” option to include everything to ensure consistency across your drawing.

  2. Define the Base Point: Utilize the coordinates (0,0) as your base point, ensuring that the scale will relate to the world coordinate system (WCS).

  3. Set the Scale Factor: Enter the scale factor relevant to switching to centimeters. For example, when converting from meters, you would use a factor of 100.

Establishing Limits in AutoCAD

1. **Open the Command Line**: Type `LIMITS` in the command line and hit Enter.

  1. Set Lower-left Coordinates: Enter the coordinates for the lower-left corner, such as (0,0), and press Enter.

  2. Set Upper-right Coordinates: Provide the upper-right corner’s coordinates, such as (200,200), and hit Enter again.

  3. Finalize with the Z Command: Type ‘Z’ and hit Enter to confirm the limits of your drawing area.

Adjusting Paper Space Scale in AutoCAD

1. **Switch to Model Space**: Change your view to the Model tab to make specific adjustments.

  1. Select the Viewport: Click on the desired viewport within the paper space.

  2. Modify Annotation Scale: On the status bar, find the annotation scale and select the appropriate scale from the dropdown menu.

FAQ

1. **How can I check what units my current drawing is using?**
– You can determine the current units by using the `UNITS` command. This will open the Drawing Units dialog, displaying the currently selected unit type.

  1. Can I change units after I’ve started drawing?

    • Yes, you can change the units at any time using the UNITS command. However, be aware that existing dimensions will convert to the new units, which might require further adjustments.
  2. What is the default unit type in AutoCAD?

    • The default unit type in AutoCAD is typically set to inches unless otherwise defined in the drawing settings. You can adjust this to metric or other unit types as required.

About the author

Wei Zhang

Wei Zhang

Wei Zhang is a renowned figure in the CAD (Computer-Aided Design) industry in Canada, with over 30 years of experience spanning his native China and Canada. As the founder of a CAD training center, Wei has been instrumental in shaping the skills of hundreds of technicians and engineers in technical drawing and CAD software applications. He is a certified developer with Autodesk, demonstrating his deep expertise and commitment to staying at the forefront of CAD technology. Wei’s passion for education and technology has not only made him a respected educator but also a key player in advancing CAD methodologies in various engineering sectors. His contributions have significantly impacted the way CAD is taught and applied in the professional world, bridging the gap between traditional drafting techniques and modern digital solutions.