How to Calculate DPI From Pixels

Techwalla may earn compensation through affiliate links in this story. Learn more about our affiliate and product review process here.
You don't need a calculator to calulate DPI.

When you see a photograph or other image on your computer monitor, you are looking at a rectangle constructed of pixels. A pixel, short for "picture element," is a tiny colored square that your computer mixes with other pixels to create images. DPI refers to the number of pixels per inch in an image. Learning to calculate DPI at various pixel resolutions can help you produce better images when you enlarge or print them.

Advertisement

Step 1

Press the "Windows" key and "E" together to open Windows Explorer. Navigate to any image file and right-click the file.

Video of the Day

Step 2

Select "View Properties" to open the "Properties" pop-up window. Click the "Details" tab. You will see values for the image's width and height in pixels. For example, the following values may appear in the window:

Advertisement

Width: 440 pixels Height: 254 pixels

Step 3

Write down those values. These are the image's pixel dimensions. Click "Close" to close the "Properties" window.and return to Windows Explorer.

Advertisement

Step 4

Right-click the image file. Select "Open With" and then select "Internet Explorer." The image will open in Internet Explorer.

Step 5

Locate a ruler and measure the image's width and height in inches.

Advertisement

Advertisement

Step 6

Divide the pixel width that you wrote down by the width in images that you measured to get the image's horizontal DPI. For instance, if the pixel width is 1524 pixels and the width in inches is six, you have this equation:

Horizontal_DPI = 1524 / 6.

Advertisement

Solving for Horizontal_DPI, you get 254 dpi for the image's horizontal resolution.

Step 7

Divide the image's pixel height by its height in images to determine its vertical DPI.

Video of the Day

Advertisement

Advertisement

references & resources