DPI — From Camera to Printer
Has your printer ever changed the size of your picture from what it was on your computer screen? Have you noticed that your printed pictures tend to look choppy? This may depend on the dots per inch, or DPI, of your digital pictures. DPI refers to how many tiny blots of color will appear in every inch of the printed image, and relates to the resolution (commonly in megapixels) of the original picture.
Quick & Simple: Windows Explorer
Right-click the image file. Select “Properties” from the context menu.
Click on the “Details” tab in the top of the pop-up. Scroll down to where you see “Horizontal resolution”, and “Vertical resolution”.