How To Change the Units Used for Guides and Rulers (Pixels, Inches, etc.) in After Effects?

After Effects empowers you to craft stunning motion graphics and visual effects, but precise control often hinges on using the right measurement system. This article equips you with the knowledge to change the units used for rulers and guides in After Effects, ensuring your creative vision aligns perfectly with your desired specifications.

Understanding Units in After Effects

Units define the scale at which elements are measured within your After Effects project. Common unit options include pixels (ideal for digital outputs), inches (used for print design), centimeters (used for metric outputs), and millimeters (offering high precision).

Units and Composition Settings:

The units you choose for rulers and guides should ideally match the units defined in your composition settings. This ensures consistent measurement across all aspects of your project. Here's how to access composition settings:

  1. Project Panel: Select the desired composition in the Project panel.
  2. Composition Settings: Right-click on the composition and choose "Composition Settings" from the context menu.
  3. Units Tab: In the Composition Settings window, navigate to the Units tab.

Default Units:

After Effects offers a default unit system based on your regional settings. However, you can customize this to suit your specific project needs.

Changing Ruler and Guide Units

After Effects provides two ways to modify the units used for rulers and guides:

Method 1: Using the Preferences Panel

  1. Access Preferences: Go to Edit > Preferences (Windows) or After Effects > Preferences (Mac).
  2. Units Tab: In the Preferences window, navigate to the Units tab.
  3. Ruler Units: Select your desired unit system (pixels, inches, centimeters, etc.) from the "Ruler Units" dropdown menu. This setting applies to both the horizontal and vertical rulers.
  4. Confirmation: Click "OK" to confirm the changes.

Method 2: Using the Rulers Context Menu

  1. Right-Click on Ruler: Right-click anywhere on either the horizontal or vertical ruler.
  2. Units Selection: A context menu will appear, displaying various unit options. Choose the desired unit system from this menu.

Benefits of Changing Units:

  • Project Accuracy: Using units that match your final output format (e.g., inches for print) ensures precise element sizing and avoids scaling discrepancies.
  • Collaboration: If collaborating with others, using a common unit system simplifies communication and avoids confusion regarding element sizes.
  • Familiarity: Choose units you're comfortable working with to streamline your workflow and avoid unnecessary calculations.

Considerations When Changing Units

  • Existing Project: Changing units after creating elements in your project might require resizing them to maintain their intended proportions.
  • Composition Settings: Ensure your composition settings (accessed as described earlier) also reflect the chosen unit system for consistency.
  • Team Communication: If working in a team, communicate any changes to the unit system to avoid confusion and ensure everyone is on the same page.

Advanced Unit Management Tips

  • Preset Management: After Effects allows you to save custom unit presets for future projects. This can save time if you frequently work with specific unit systems.
  • Third-Party Plugins (Optional): Explore third-party plugins that offer additional unit conversion and management functionalities within After Effects.


By mastering the art of changing units for rulers and guides in After Effects, you can ensure your creative vision translates flawlessly into the desired format. Remember, the chosen unit system plays a crucial role in project accuracy and efficient collaboration. So, don't be afraid to experiment with different units to find the perfect fit for your workflow!

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