What DPI Should I Use for Print?

pixels = inches × DPI

A 4 × 6 inch photo at 300 DPI needs:

4 × 300 = 1200 px
6 × 300 = 1800 px

So the file should be 1200 × 1800 px for a 300 DPI target.

1. Start with the final physical size. 2. Decide how close people will view it. 3. Check the printer or lab requirements. 4. Calculate the required pixels. 5. Compare the requirement to your source image. 6. Crop and resize only after confirming the aspect ratio. 7. Export a proof if the job matters.

600 DPI can make sense for:

• scanning old photos;
• archiving artwork;
• fine line art;
• specialist print workflows;
• images that may be cropped later;
• cases where the printer specifically requests it.

For ordinary web uploads or standard print products, 600 DPI often creates larger files without a visible improvement.

150 DPI can be acceptable for large-format designs such as posters, banners, signs and event graphics when viewers stand farther away. A 3 × 6 ft banner at 300 DPI would create a very large file, and the extra detail may not be visible from normal viewing distance.

Use 150 DPI when:

• the print is large;
• the viewing distance is several feet or more;
• the printer recommends it;
• the file would become impractically large at 300 DPI.

300 DPI is the safest default for:

• business cards;
• flyers;
• brochures;
• postcards;
• menus;
• photo prints;
• resumes and office documents;
• small posters viewed up close.

It is widely understood by designers, print shops and photo labs, and it usually gives enough detail for close viewing.

PPI means pixels per inch in the digital image. DPI often refers to dots per inch in printer output. In everyday print setup, people often say “DPI” when they mean the image resolution target. PixelMeasures shows DPI/PPI together because the practical file-preparation question is: how many pixels are available for each printed inch?

A common mistake is changing a file from 72 DPI to 300 DPI and assuming the image is now high resolution. The file only becomes better if it has enough real pixels.

For example, a 600 × 900 px file can print as:

The same file has the same pixel data. The print size changes how dense those pixels are.