A digital image is a rectangle made up of many small squares of color called pixels.  The number of
pixels across the width and height of the image is called the resolution. An image with 640 pixels across
the width and 480 pixels high has a resolution of 640x480.  The more pixels in the image file, the higher
the resolution.  The larger the file resolution, the fewer images that will fit on your camera memory card.
Commonly the size of a digital camera image is proportionate to a 4x5.3 not a 4x6.

Resolution Table

taking photos, always set your digital camera to the highest resolution possible. This will help to ensure
taking photos, always set your digital camera to the highest resolution possible. This will help to ensure
that your prints will look nice. Also indoors always use a flashthat your prints will look nice. Also indoors
always use a flash
MegaPixel
Image Resolution  
Outstanding Print
* fine compression  
Very Good Print  
Fair Print
1
480 x 640
--
Wallets
4x6
1.2
788x1024
Wallets
4x6
5x7
1.5
1024x1280
3x5
5x7
8x10
2
1200x1600
4x6
8x10
10x15
3
1536x2048
5x7
8x12
12x18
4
1800x2400
6x9
12x18
16x20
5
1932x2580
6x9
12x18
16x24
6
2013x3040
8x10
12x18
20x30
7.1
2304x3072
8x12
16x24
24x36
8.3
2336x3504
10x15
20x30
30x40
10.2
2592x3872
11x14
24x30
30x40
10.9
2704x4060
11x14
24x36
36x48
16.6
3328x4992
12x18
36x48
48x64
How big can I print from my digital camera?