DPI: Photo 8 x 12

Use this calculator to find out how many pixels (resolution) an image should have to be printed at a certain size.

Print Dimensions

Net dimensions (no bleed)
203.2 mm x 304.8 mm = 61935.36 mm2aspect ratio: 0.667 (diagonal: 366.32 mm)
20.32 cm x 30.48 cm = 619.35 cm2aspect ratio: 0.667 (diagonal: 36.63 cm)
8 inch x 12 inch = 96 inch2aspect ratio: 0.667 (diagonal: 14.42 inch)

Print Pixel Size

Dots-per-inch
Printer resolution = 300 dpi = 118 dots/cm
Printer pitch = 85 µm / micrometer (size of 1 pixel)
Net dimensions (no bleed)
2400 px x 3600 px = 8.6 megapixels
= aspect ratio 0.667

Some examples

References