How to Adjust DPI on a JPG

By Kris Borinski

The computer leapfrogged 20th century technology to a level never before witnessed in industrial society. As personal computers became commonplace, along with them came a new language and learning curve. Most home users are now left to learn how to do necessary tasks on their own, with little to no formal training. Adjusting Dots Per Inch (DPI) on a digital photo is not hard to do, but without a working knowledge, the task can be daunting.

Things You'll Need

  • Digital photos
  • Computer
  • Windows or Macintosh operating systems

Adjusting DPI on a Digital Photo

Step 1

Attach the digital camera to a Universal Serial Bus (USB) port via a USB cable. Some computers also have a Secure Digital (SD) slot built in. Take the SD card out of the camera, and then put in the slot. Another method is to use a card reader device that connects to the computer via a USB port, and the digital card is inserted into the reader.

Step 2

Copy the photos to the computer. Open the source of the photos by double-clicking on it. Name a folder with a date or subject on the computer. With the source location open, select the photos and drag them to the computer file.

Step 3

Adjust the size of the photo. On Windows operating systems, find the folder the photos are in and select those you want to adjust. Hold down the “Shift” key when selecting multiple images. The selected ones will be highlighted. Right-click with the mouse. A dialog box will open with an option labeled “Resize Pictures.” Choose it, and a new box will appear with several size options. Select one and click “OK.” The software adjusts the size and the DPI for the photo based on the selection made.

Step 4

Adjust the size of the photo on a Macintosh. Using the current operating system of Mac OS 10.6, find the folder with the images and click on one to open it. From the top menu, click on “Tools,” select “Adjust Size” and either select a size from the drop down menu in the “Fit Into” box or enter you own numbers.

Step 5

Choose a resolution. The most common resolutions are 72, 150 and 300 DPI. For onscreen displays, 72 DPI is fine. For printing, 150 DPI or 300 DPI are better options. As you change the resolution number, watch the final size of the photo change.