There are several ways to calculate print resolution, depending on the answer you want. Let's say you wanted to know the print size at 212 DPI for a digital image measuring 2048 x 1536 (3.1MP). You can simply divide the image's resolution by the print resolution (DPI) to give a final printed size in inches: 2048 pixels / 212 DPI = 9.66" and 1536 pixels / 212 DPI = 7.25". This means that if you print a digital image measuring 2048 x 1536 onto a paper measuring 7.5" x 10" (rounded), you will have a 212 DPI print.

If you need to know the size of a digital image for a specific print size and resolution, you can run this formula backwards. For example, let's say you wanted a 5" x 7" print with a print resolution of 300 DPI. All you need to do is multiply the print size by the print resolution: 5" x 300 DPI = 1500 pixels and 7" x 300 DPI = 2100 pixels. This means you need a digital image at least 2100 x 1500 pixels to get 300 DPI on a 5" x 7" print.

The aspect ratio of a picture becomes important when you want to print it. Different size prints, like a 4" x 6" or 8" x 10" print, have different aspect ratios. The size of the print may, or may not, correspond to the aspect ratio of the original picture. If it doesn't, some parts of the picture may have to be sacrificed, or the paper trimmed to the picture's size.

An aspect ratio represents the relationship between the width and height. For example, you have a 4" x 6" print, it's aspect ratio would be 1.5:1 (6" / 4" = 1.5), or 1.5" of width for every 1" of height. An aspect ratio of 1:1 is a perfect square. You can also get the aspect ratio of a picture by using it's resolution. For example, if you have a picture with a resolution of 2560 x 1920, it's aspect ratio will be 1.33:1 (2560 / 1920 = 1.33).

The aspect ratio of different print formats varies considerably. For example, a 4" x 6" print has an aspect ratio of 1.5:1, whereas an 8" x 10" print has an aspect ratio of 1.25:1. This means you cannot directly scale a 4" x 6" print to an 8" x 10" print. If you don't want to loose any part of the picture (usually refered to as 'cropping'), you'll get a 6.6" x 10" picture on an 8" x 10" paper. This leaves some white bars on either side, which you'll probably want to trim away. Another alternative is to 'crop' the picture to a 1.25:1 aspect ratio, so it will completely fill the 8" x 10" print. This will mean loosing some parts of the original picture.

Here are some common aspect ratios, and how they appear (without cropping) on a number of print formats:

Ratio	Print Formats
	4" x 6"	5" x 7"	8" x 10"
1.5:1	4" x 6"	4.6" x 7"	6.6" x 10"
1.33:1	4" x 5.3"	5" x 6.6"	7.5" x 10"

As you can see, pictures with an aspect ratio of 1.5:1 are better suited to 4" x 6" prints, and those with an aspect ratio of 1.33:1 are better suited to 8" x 10" prints. In most cases, the pictures on MVPix.com have an aspect ratio of 1.33:1, making them more suitable for 8" x 10" prints (the prefered size for framing).

Whatever the aspect ratio, you should always avoid cropping a picture to fit a particular print size. Instead, remove the excess paper from the print afterwards. Most digital photography labs allow you to disable automatic cropping. Look for this option when ordering prints.

A photographic print is created by laying a number of colored dots onto paper. The more dots per square inch (DPI), the better the print will look. If the print resolution (DPI) isn't high enough, the photo can look a little grainy. The printing process will usually dictate the minimum print resolution required. digital photography labs often recommend a print resolution of 212 DPI or more for their process.

A photographic print is created by laying a number of colored dots onto paper. The larger the surface, the more these dots have to be spread apart to fill the surface. At a certain point, the photograph will start to look grainy and less apealing. Some printing processes need more dots per square inch to produce a quality image. Magazine editors often require 300 DPI or more, while digital photography labs usually recommend a minimum print resolution around 212 DPI or more for their process.

Using an example of 212 DPI, you can get the maximum print size by dividing the file's resolution (in pixels) by 212. If an image file is 2560 pixels wide by 1920 pixels high, the print size at 212 DPI would be 12" x 9" (2560 / 212 = 12 and 1920 / 212 = 9).

There are several excellent online photo labs on the internet. You can have your photos printed on photographic paper, in various sizes (4"x6", 8"x10", 11"x14" and even larger), on coffee mugs, mouse pads, t-shirts, etc. The quality of photographic prints from most online photo labs is excellent, and compares favorably with professional prints from 35mm film.

Some photo labs we recommend are ez prints and Shutterfly.