DPI calculator: Photo 4 x 6

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)
101.6 mm x 152.4 mm = 15483.84 mm2 (diagonal: 183.16 mm)
10.16 cm x 15.24 cm = 154.84 cm2 (diagonal: 18.32 cm)
4 inch x 6 inch = 24 inch2 (diagonal: 7.21 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)
1200 px x 1800 px = 2.2 megapixels
= aspect ratio 0.667

Some examples