Adobe Photoshop’s rulers are very useful when you crop, combine, or otherwise edit your images. Depending on what you’re doing, you may want them to display pixels, percentages, or even inches. Here’s how to change their units.
How to show rulers
If you don’t see the rulers at the edge of your document, go to View> Rulers, or use the keyboard shortcut Control + R (Command + R on a Mac).
You can hide the rulers if you don’t need them. Use the same commands.
How to Change Ruler Units
Adobe Photoshop supports seven unit types:
- Picas (1 pica = 12 points)
- Per cent
The fastest way to switch between the two is to right-click on a ruler and select the desired option from the drop-down menu.
You can also change the unit from Photoshop preferences. Go to Edit> Preferences> Units and Rulers. (On a Mac, go to Photoshop> Preferences> Units & Rulers.)
Under “Units”, click the “Rulers” drop-down list, then select the units you want to use.
Note: When you change ruler units in one document, they change in all of your open Photoshop documents.
Can you change the default ruler units?
Unfortunately, there is no way to change or set the default ruler units to match the dimensions of your images. Photoshop remembers the last unit you used.
Can you set different ruler units for different documents or presets?
Again, unfortunately not: you cannot set different ruler units for different documents in the application. The ruler unit is a global setting. If you change it in one Photoshop document, it will be changed in all Photoshop documents.
(Yes, this is super annoying when you’re editing images and laying out print designs at the same time.)