To find the DPI of an image on a MAC, you will first need to right-click on an image and click on "Get Info," followed by a click on "More Info." In the tab, look for dimension as "Width Pixels x Height Pixels." In the next step, we will determine the width and height of the image in inches. We will then divide the Width Pixel with the Width of the image to get Horizontal DPI and divide the Height Pixel with the height of the image to get the Vertical DPI of the image.