Print Sizes and Camera Resolutions

As a general guide, at 320-ppi printer resolution (as in the case for the Costco Noritsu QSS-3411):

for 4"x6" print:  you need 2.5 megapixels of camera resolution (4 x 320 x 6 x 320 = 2,457,600 pixels)

for 5"x7":  3.6 MP

for 8"x10":  8 MP

for 11"x14":  16 MP

for 16"x20":  33 MP

If you send a file that has a larger camera resolution than needed for the print size that you requested, Costco will simply resize it down before submitting it to the printer, to reduce bandwidth and storage.

If your file has a lower resolution than that is needed for the print (for example, you want to print a 16x20, and you have only a 8-MP file), the printer will interpolate.