Adobe Illustrator 2024 introduced the Dimension tool in Illustrator, which has seen several updates and improvements since its release. This tool allows you to add linear, angular, and radial dimensions to your drawings. These dimensions remain live and update automatically as you scale your artwork.

For a demonstration and overview of the concepts I cover in this post, check out the video tutorial above.

Getting Started with the Dimension Tool

To begin using the Illustrator dimension tool, click on the tool to open the taskbar. From there, you can select a specific dimension type or click the gear icon to access the tool options dialog.

Understanding the Dimension Tool Settings in Illustrator

The key to using this tool effectively is understanding the settings. When you style a dimension with line weights, arrowheads, and a font, those settings apply to the individual dimension objects as you create them. There is no global or document-wide style settings panel for dimensions.

This is why updating the styling of dimensions across your document is a process of working between two settings locations: the Dimension Tool Options dialog (gear icon on the taskbar) and the Properties panel (Window > Properties).

Illustrator Dimension tool options dialog

1. Dimension Tool Options Dialog

The settings in this dialog (shown above) apply to any new dimension objects you create, regardless of the document you are working in. Here, you can set styling options such as line weights, arrowheads, colors, and fonts. Additionally, this dialog includes settings for the unit of measure, precision, and scaling ratio. The Dimension Tool Options dialog is the only place to set a scaling ratio for your dimensions.

Properties panel Illustrator Dimension tool quick actions

2. Properties Panel and Settings Update Buttons

The Properties panel (shown above) displays the settings for the selected dimension object. It contains many of the same styling settings (line weights, arrowheads, font size) as the Dimension Tool Options dialog.

To change all dimensions in your document to a new style or setting, select a dimension object with the desired settings and click the quick action "Apply to All” button. To update the Dimension Tool Options dialog with the selected dimension style for future dimensions, click "Set as Default."

Note that the Properties panel does not include a scaling ratio setting. To change the scaling ratio of existing dimensions, you need to re-create them by setting the new scaling ratio in the Dimension Tool Options dialog and creating new dimension objects.

Using the Dimension Tool in Adobe Illustrator

To create a dimension, choose Linear, Angular, or Radial on the taskbar, then hover over a path and click-drag to create the dimension.

dimension tool illustrator creates a separate layer for dimensions

Dimensions are automatically placed on a separate Dimensions layer. Be mindful of which layer is selected as you create new art because drawing on the Dimensions layer is possible. This won’t harm anything, but it can make your document less organized.

Dimension objects remain live and will automatically update as you scale the paths they are attached to. To avoid expanding a dimension object, only use the Dimension tool to reposition it. Using the Selection tools to move a dimension object will expand it into its component parts, paths, and live font type.

Linear Dimensions

Hover over a path to see a pink guide of the dimension, then click-drag to create and place the dimension object. Dimensions automatically read the (unlocked) artwork, sensing dimensions between corner points.

To dimension one panel of the box shown above without automatic measuring between the corner points, you can manually plot any distance by clicking two points and dragging out the dimension object.

Tip: Keep the ESC key handy to reset the pink guide and start again.

Tip: Hold Option/Alt and click to create width and height dimensions simultaneously.

Angular Dimensions

Hover and click-drag over a corner point to place an angle dimension. You can manually create dimensions if the angle does not have a corner point. The lines that make up the angle must intersect. Click the line on either side of the angle, drag to see the pink guide, and click to place. Drag inward for an interior angle and outward for an exterior angle.

Radial Dimensions

Radial dimensions can only be created on perfect circles or arcs. Hover on the circumference, then click-drag inward to dimension the diameter or outward for the radius.

Dimension Styling and Precision Settings

Styling settings are mostly self-explanatory. You can change the color, line weight, and font settings to style your dimensions.

The basic components of a dimension object in Adobe Illustrator include:

Dimension Line: Shows the dimension as a line with arrows on both ends.
Extension Line: Perpendicular to the dimension line. Drag to determine its length.
Dimension Text: Labels the dimension.

For extension lines, “Offset” controls the space between the extension lines and the path you are dimensioning. “Extension” controls the length of the line that extends past the dimension line.

To update styling globally across your document, select a dimension object, and in Properties, click "Apply to All." Click "Set as Default" to style new dimension objects.

Precision

Dimensions can contain up to 3 decimal points, or in the case of feet and inches, 1/4” precision. This may not be precise enough for some projects, so be sure to let Adobe know on the Illustrator User Voice forum: Dimension Tool Precision Menu Needs More Precision.

Custom Scaling

Click the gear icon on the Dimension tool taskbar to open the options dialog, choose a ratio from the scale menu, or select Custom to create your own.

For the studio plan drawing above, I used a 1” = 1 foot scaling. I clicked the ggear icon in the taskbar to set a custom scaling ratio of 1:12 and set the units to feet and inches.

Changing the scaling in the Dimension Tool Options will apply the new scaling to any new dimensions you create. To update existing dimensions to a new scale, you will need to recreate them.

Dimension Preset Workaround

Currently, there is no option to save a preset. As a workaround, open a document with a style you want to use, select the dimension object, and in Properties, click "Set as Default" before returning to your new document.

an illustrator document with multiple dimension styles

I created a separate document called “My Dimension Styles” with various dimension styles I like, so I can quickly change styles without having to revisit every setting.

Check the Dimension tool guide at Adobe Help for updates. To upvote dimension presets as a feature, visit: Dimension Tool Style Presets.

Enjoy Using the Dimension Tool in Illustrator

I hope this guide helps you get the most out of the new Dimension tool in Adobe Illustrator. Happy designing, and feel free to share your creations and any tips you discover along the way! - Laura Coyle