What is DPI? Easily explained

The term DPI is often used to refer to photos and their properties. We explain what DPI is and what the abbreviation actually stands for.

Simply explained: what is DPI?

The abbreviation is not only used in the field of digital photography, but also for information on screens or print settings.

1. The term DPI stands for "dots per inch". Thus, it indicates a density of dots related to an inch, where one inch is approximately 2.54 cm.
2. The abbreviation PPI is also common, in which the first "P" stands for "pixel" instead of "dot". You will therefore often read the designation with pixels on monitors or scanners. For printers that actually print dots and not pixels directly on paper, you must use the term DPI.
3. It is important that it does not make sense for image processing if you only specify PPI or DPI, you must always relate the pixel density to a desired image size. The information in the meta files is usually only a rough recommendation.
4. For example, if you want to print a poster of 70cm * 100cm with a pixel density of 150 PPI, you first have to find out what resolution the image must have so that it doesn't look grainy afterwards.
5. With the help of the required PPI and the desired size of the poster you can calculate which resolution the image should have.
6. In the photo you can see the formula with the sample values ​​used. As a result, you get that the source image should have a resolution of approx. 4000x6000 pixels.

We also explain how you can increase the DPI in photos.