How to Set Exact Guides in GIMP by Pixels or Percent

This guide explains how to place guides at exact pixel coordinates or percentage positions in GIMP using the application's built-in menu options. Rather than dragging guides manually from the rulers, GIMP allows you to input precise numerical values, ensuring pixel-perfect alignment for cropping, designing, and arranging layout elements.

Adding a Guide by Exact Pixel Value

To add a guide at a specific pixel location:

  1. Open your project in GIMP.
  2. In the top menu, go to Image > Guides > New Guide....
  3. In the dialog box that appears, select the Direction of the guide (Horizontal or Vertical).
  4. Enter your desired numerical coordinate in the Position field. By default, this value is measured in pixels (e.g., entering 500 places the guide at the 500-pixel mark).
  5. If you prefer a different unit of measurement, such as inches, millimeters, or points, use the drop-down menu next to the numerical field to change the unit.
  6. Click OK to place the guide.

Adding a Guide by Percentage

If you need to place a guide relative to the image canvas—such as finding the exact center or marking thirds:

  1. In the top menu, go to Image > Guides > New Guide (by Percent)....
  2. Select the Direction (Horizontal or Vertical).
  3. Enter the desired percentage in the Position (%) field. For example:
    • Enter 50 to place the guide directly in the center.
    • Enter 33.33 to mark the first third of the canvas.
  4. Click OK to apply the guide.

Managing and Removing Guides

  • Hide/Show Guides: Toggle guide visibility by navigating to View > Show Guides or pressing Ctrl + Shift + T (Cmd + Shift + T on macOS).
  • Snap to Guides: Ensure layers and tools snap accurately by checking View > Snap to Guides.
  • Clear Guides: Remove all placed guides at once by going to Image > Guides > Remove all Guides.