A6 at 150 DPI is 620 × 874 pixels

A6 (105 × 148 mm) at 150 DPI is 620 × 874 pixels, which is 0.54 megapixels.

Portrait620 × 874 pixels
Landscape874 × 620 pixels
With 3 mm bleed656 × 909 pixels
Megapixels0.54
Aspect ratio1.41:1 (1 to √2 before rounding)
File size1.6 MB as uncompressed 8-bit RGB; a JPEG or PNG is smaller
Paper size105 × 148 mm (4.13 × 5.83 in)

The working

Pixels are inches multiplied by the resolution, and an inch is 25.4 mm.

Bleed is extra image past the trim line, so that a cut that lands slightly off still leaves ink to the edge. Print shops usually ask for 3 mm on every side of an A-series page, which makes the file 656 × 909 pixels.

Is your photo big enough?

To fill A6 at 150 DPI an image needs at least 620 × 874 pixels. Cropped to fill the sheet:

At 150 DPI the pixels of a print blend together from about 22.9 inches (58 cm) away. 150 DPI is a common minimum for posters and large prints seen from a step or two away, and a usual setting for scanning documents that only need to be read.

A6 at other resolutions

ResolutionPixelsWith bleedMegapixelsUncompressed
72 DPI298 × 420315 × 4370.13367 KB
96 DPI397 × 559420 × 5820.22650 KB
100 DPI413 × 583437 × 6060.24705 KB
150 DPI620 × 874656 × 9090.541.6 MB
200 DPI827 × 1165874 × 12130.962.8 MB
240 DPI992 × 13981049 × 14551.44 MB
300 DPI1240 × 17481311 × 18192.26.2 MB
400 DPI1654 × 23311748 × 24253.911 MB
600 DPI2480 × 34962622 × 36388.725 MB
1200 DPI4961 × 69925244 × 72763599 MB

Other sizes at 150 DPI

A6 is a quarter of A4, the size of a postcard. See A6 in pixels at every resolution or everything at 150 DPI.