How to Scale Multiple Objects in AutoCAD (Complete Guide)

In AutoCAD, scaling multiple objects can be necessary for adjusting the size of components, correcting drawings that are not at the right scale, or converting between different unit systems. This guide provides a step-by-step approach to scaling multiple objects, with tips for beginners and detailed explanations for more complex tasks.

How to Scale Multiple Objects in AutoCAD

Step 1: Selecting the Objects

Before you begin scaling, you need to select the objects you wish to resize. AutoCAD offers several methods for selecting objects.

1. Basic Selection:
   • Use the Select tool or type SEL in the command line.
   • You can also drag a window around the objects you want to select. A green window (selection from left to right) will include all objects it touches, while a blue window (selection from right to left) will only select objects entirely within the box.
2. Advanced Selection:
   • For more complex drawings, use Select Similar to quickly choose multiple objects of the same type, such as all lines, blocks, or hatches.
   • You can also use the FILTER command to apply filters based on object types, layers, or other properties.

Pro Tip: Learning how to refine your selection is crucial when dealing with large drawings, as it helps you manage complex designs more efficiently.

Step 2: Starting the Scale Command

Once your objects are selected, initiate the Scale command:

1. Type SCALE in the command line and press Enter.
2. Alternatively, go to the Modify tab in the ribbon and select the Scale tool.

This command allows you to either resize based on a factor or to scale using a reference, depending on your needs.

Step 3: Setting a Base Point

After activating the Scale command, you will need to define a base point. This is the reference point from which all objects will be scaled.

• Why It’s Important: The base point acts as the “anchor” for your scaling operation. If you choose a corner or an edge as the base point, the scaling will extend outward from that spot. On the other hand, choosing the center of your objects will allow them to scale evenly around the base point.

Pro Tip: Always choose the base point carefully, especially when working with precise drawings. A wrong base point can cause objects to shift out of place, creating unnecessary work to reposition them.

Step 4: Scaling with a Factor

In many cases, scaling objects by a numerical factor is the simplest method. Here’s how it works:

1. Input a Scaling Factor:
   • After selecting the base point, AutoCAD will prompt you to input a scale factor.
   • For example, if you want to double the size of your objects, type 2. To reduce their size by half, type 0.5.
2. Press Enter to apply the scale factor.

Example: If you’re scaling furniture in a room layout from 1:50 to 1:100, inputting 0.5 as the scaling factor will reduce the objects proportionally.

Step 5: Scaling with a Reference

In more complex situations where you need to match an object’s size to a specific length, you can use the reference method.

Here’s how to scale using a reference:

1. Select the Reference Option: After entering the SCALE command, type R for Reference.
2. Choose the Reference Points: Click two points on an object that represents the known size. For example, select both ends of a line whose correct length you know.
3. Specify the New Length: Enter the actual length you want the object to be scaled to. AutoCAD will calculate the necessary scale factor and apply it automatically.

When to Use: This method is ideal when you need precise scaling without knowing the exact scaling factor in advance. It’s especially useful when adjusting to real-world dimensions, like resizing architectural drawings.

Step 6: Rescaling Drawings Using Units

In some cases, you might need to rescale a drawing when working with different units, such as converting between inches and millimeters. AutoCAD provides tools to handle these conversions effectively.

Method 1: Using the -DWGUNITS Command

1. Type -DWGUNITS in the command line.
2. Follow the on-screen prompts to choose the appropriate units (e.g., millimeters, inches, feet).
3. AutoCAD will ask if you want to scale objects to match the new units. Enter Yes to automatically adjust the drawing.Pro Tip: This method is ideal for converting an entire drawing from one unit system to another, such as switching from imperial to metric.

Method 2: Using the Scale Command for Unit Conversion

1. Use the SCALE command as usual.
2. When prompted, enter a conversion factor based on the units:
   • Inches to Millimeters: 25.4
   • Feet to Millimeters: 304.8
   • Millimeters to Feet: 0.00328084

Note: After scaling, you may need to adjust dimension styles and viewport sizes to reflect the new scale.

Step 7: Verifying the Scaling

After completing the scaling process, it’s important to verify that the objects are correctly resized. You can do this by:

1. Using the Distance Tool:
   • Type DIST in the command line to measure the new size of an object.
2. Adding Dimensions:
   • Use the DIM command to place dimensions on objects, ensuring that they match the intended scale.

Pro Tip: If you’re working in a layout or paper space, make sure to check your plot scale settings to ensure that everything prints at the correct size.

Conclusion

Scaling multiple objects in AutoCAD is a fundamental skill that can be done with ease when following the correct steps. Whether you are using a simple scale factor or adjusting based on a specific reference, these methods ensure that your drawings remain accurate and to scale. Don’t forget to verify your results and adjust your layouts if necessary, especially when converting between unit systems.