Lesson11: Dimensioning in AutoCAD

Dimensioning in AutoCAD

You can create different types of dimensions in AutoCAD, and you can also save dimension settings under a name for future use.

Below is an example showing various dimension types using an architectural style in imperial units (feet and inches).

Linear Dimensions

With the DIM command, you can create several types of dimensions:

• Horizontal
• Vertical
• Aligned
• Radial

The type of dimension you get depends on:

• What kind of object you select
• How you move your cursor when placing the dimension

Example 1: Quick Dimension from a Line

Here’s how to use the DIM command to create a dimension:

1. Start the DIM command.
2. Click on the object or line you want to dimension.
3. Then click again where you want the dimension line to appear.

That’s it! You’ll get a dimension showing the measurement between the points you selected.

Example 2: Dimension Between Two Points

Let’s say you want to show the distance between two points:

1. Start the DIM command.
2. Click the first point.
3. Click the second point.
4. Then click a third time to place the dimension line.

Tip: To keep your dimensions lined up neatly, snap the dimension line to the end of a previous dimension. That keeps your drawing looking clean and professional.

Keep It Horizontal

If your two points aren’t aligned horizontally and you still want the dimension line to stay horizontal, just hold down the Shift key while placing the dimension line. This forces the line to stay level.

But if you’re working on something that’s not horizontal—like a slanted wall—you should use the DIMROTATED command instead. It lets you create dimensions that follow the angle of the object.

Angled Dimensions

You can also use the DIM command to make dimensions that follow an angle. To do this, just drag the dimension line at an angle, not straight up/down or left/right.

Pro Tip: Be careful when snapping to points. Zoom in close so you don’t accidentally select the wrong object or part of another dimension. This is a common beginner mistake.

Editing Dimensions

Sometimes you need to adjust your dimensions. The fastest way to do this is by using grips.

Here’s how:

1. Click on the dimension to select it.
2. You’ll see blue squares appear — these are grips.
3. Click on the grip in the middle of the text to move the text.
4. Or click on one of the grips at the ends of the dimension line to move the whole dimension line.

Tip: If you need to make a lot of changes, it might actually be quicker to delete the dimension and start over rather than adjusting everything manually.

Dimension Styles

Dimension styles are used to keep all your dimensions consistent and professional. You can control every detail about how a dimension looks by using the DIMSTYLE command.

These styles save settings like:

• Text size
• Arrow size
• Line spacing
• Units and scale

When you create a dimension style, you can use it again and again, and it will apply the same settings automatically.

By default, AutoCAD gives you:

• Standard style for imperial units
• ISO-25 style for metric units

When you create a new dimension, it uses whatever current style is active. The name of the current style appears in the Annotation panel (in this example, the style is named “Hitchhiker”).

Opening the Dimension Style Manager

To open the Dimension Style Manager:

• Click the button on the Annotation panel (the one next to the style name).

Here, you can create your own dimension styles to match your project standards or industry requirements.

Warning: Creating a new style takes time because you need to set up all the details. That’s why it’s a good idea to save your custom styles inside your drawing templates (.DWT files) so you can reuse them easily.

Final Recommendations

• Always give your styles a clear, descriptive name so you remember what they’re for.
• Check with your CAD manager (if you have one) to see if there are already-approved styles or templates you’re supposed to use.