Killer Web Site of the Day: Megapixel Calculator

You've got a 800 x 600 pixel image file. How big can you print it out at the highest quality? And how much space will it take up as a JPEG, a RAW file, or a GIF?

All these questions are answered immediately in the Megapixel Calculator, a must-bookmark resource for anyone who frequently works with digital images.

Just click over to the site, enter your image's width and height, and you'll immediately receive a number of pieces of information: The size of the file under a variety of formats, how many of those files you could fit on a variety of memory cards of standard sizes, how much each second of video at that resolution would consume, and—the best feature on the site, if you ask me—how large you can print out the image at screen, "normal," and high resolution. (In the case of my 0.5-megapixel example, that's a mere 2.7 inches by 2.0 inches at high res, which is what I'd recommend you look at if you're considering printing any photos.)

Killer stuff, and it can be a huge help in letting you decide how to set your digital camera based on what you ultimately want to with the images you shoot. (Want to print 8 x 10-inch photos? You'll need at least 7 megapixels or more for high-res printouts.) Nothing to install, and a brain-dead-simple interface. Click the "megapixel resolution chart" link as well for easy access to this information for many common resolutions.

UPDATE: To all who dispute that you need 7MP to produce an 8x10, this is a (painfully) simple math problem: A standard  7.1MP camera produces images that are 3072 pixels wide and 2304 pixels high. At a standard printing resolution of 300 dots per inch, that makes an image that is 10.2 inches wide and 7.7 inches tall at full resolution. If you try to create an image bigger, the printer will have to interpolate and print out at lower than 300dpi. That may indeed make for a passable print depending on the quality of the printer and the shot, but most viewers will notice the difference. That said, my intention with this post was not to dredge up the megapixel debate but to point users to a source where they can do these kinds of calculations easily. I am not affiliated with the linked website.