For my Mac’s settings, (1800 pixels / 11.875 inches) * 2 = 303 ppi, and entering that in Screen Resolution lets Print Size show the Photoshop ruler at an on-screen size that matches a real ruler.Īlso important: For both Actual Size and Print Size to work properly, the document physical dimensions in inches/cm and the PPI resolution (you set both in Image > Image Size) must match the final reproduction dimensions and resolution. For a Retina/HiDPI display, take the pixel width from the UI scaling selected in Displays, as gener7 showed, and then after doing the calculation, double the result to compensate for 2x pixel density so that you get the correct number for Screen Resolution. How adjusting this virtual ruler to actual size You can adjust the size in two ways: The first: To adjust the size of the ruler by select the size of your monitor. Important: It gets tricky on a Retina (macOS) or HiDPI (Windows) display, which use 2x pixel density. Also See: Online Ruler(MM,CM,INCH) MM(CM) Ruler Inch Ruler 1/8 Inches Ruler 1/16 Inches Ruler 1/32 Inches Ruler MM to Inches. If you don’t know the display resolution, you can work it out yourself using the method gener7 showed earlier in this thread. scale by multiplying the feet portion by 12 (inches/foot). The smallest unit on an Imperial ruler is the 1/12th of an inch. The Imperial ruler is marked in inches, with each inch subdivided into smaller units. The Imperial system is used in many countries but is most commonly associated with the United Kingdom. If Actual Size is not accurate, use View > Print Size after manually calibrating it by entering your screen resolution in Preferences / Units and Rulers / Screen Resolution. You can also add the real size and scaled size to find the scale factor. An Imperial ruler is a ruler that uses the Imperial system of measurement. It does match up perfectly when your eye is directly above each marker.)Īctual Size might not be accurate with some computer and graphics hardware combinations. Scaling long online on-screen ruler Dont know your screen size 15' 17' 19' 20' 22' 24' 26' 27' iPhone 4 iPhone 5 iPad (2, 3, 4) iPad mini Macbook 13.3' or Macbook Air pre 2010 Macbook Pro 15. (It may look slightly off in the photo, but that is due to close up parallax. And you don’t have to know what any of the numbers are, it just works. When Actual Size is used, Photoshop gets the display pixel density from the Mac hardware, and uses that to correct the display magnification, so the Photoshop ruler matches the real ruler that is against the screen. This results in a quotient of 0.3125, which is the decimal representation for 5/16 of an inch. For instance, when converting 5/16 of an inch into a decimal, you would divide 5 by 16. The screen shot posted earlier by gener7 is from a Mac.īelow is the ruler in Photoshop on my MacBook Pro after choosing View > Actual Size in Photoshop. Then, simply perform the division to obtain the decimal representation of the fraction. The Actual Size command works automatically on a Mac.Īll of the replies I posted are from my Mac.

5 inch ruler life size