DPI/PX Calculator

Below one will find:

A short discussion on the importance of DPI/Pixel settings right prior to printing,

A table of pre-determined values for large format printing, 

The formula used in the calculations, and an

Automatic calculator for the user’s convenience.

When uploading an image file online to a poster printer or photographic print producer, the following table should prove useful.  If your image is not formatted with the printing company’s required DPI settings, it likely disappoint with result when you receive a pixelated image.

I recommend calling your printer  prior to uploading an image file file in order to inquire as to what specifications are needed to print a non-pixelated poster, or large format photograph.  Also ask them if they compress your hi-resolution images prior to printing in order to save ink.  Just because you upload a high quality image does not therefore preclude an unscrupulous printer from rendering it low-quality prior to printing.   After all, they are printing for profits.

Picture Size in Inches” Pixels(px) required for 150 DPI  Pixels(px) required for 300 DPI 
4 x 6 600 x 900 1200 x 1800
5 x 7 750 x 1050 1500 x 2100
8 x 10 1200 x 1500 2400 x 3000
11 x 14 1650 x 2100 3300 x 4200
16 x 20 2400 x 3000 4800 x 6000
20 x 24 3000 x 3600 6000 x 7200
24 x 36 3600 x 5400 7200 x 10800
36 x 48 5400 x 7200 10800 x 14400
48 x 72 7200 x 10800 14400 x 21600

Formula for calculations:

Multiply the picture size or width  and height dimensions by DPI or (W x DPI) and (H x DPI).

  • Example for 20 x 30 at 150 DPI: (20 x 150)=3000 (30 x 150)=4500
  • Example for 20 x 30 at 300 DPI: (20 x 150)=6000 (30 x 300)=9000