Convert pixels to inches (Output to Monitors/Printers)
Formula: Pixels DPI = Inches

Image Width: Pixels
Image Height: Pixels

Select the resolution
of the output device
Image Width: inches
Image Height: inches

Convert inches to Pixels (Input from Scanners)
Formula: Inches X DPI = Pixels

Photo Width: inches
Photo Height: inches
  
Select the DPI setting
of the Scanner
Image Width: Pixels
Image Height: Pixels