What Is 8 1/2 Inches by 11 Inches in Pixels?
By Danielle Fernandez
The availability of reasonably priced digital cameras and smartphones with photo capabilities has made printing your own photos commonplace. It's often frustrating, though, to find that larger prints come out grainy and poor in quality. The default photo resolution on most devices is less than a third of what is required for a good, clean enlarged print, and even the best editing software is only able to provide minimal improvement. To avoid graininess when printing an image on a letter-sized sheet of paper, maximize your resolution to ensure a sharp, clear printed copy.
Meaning of Pixels
A blend of the words "pictures" and "element," pixels are dots arranged in rows and columns to make up an image. Digital images contain hundreds, thousands, even millions of these little dots of colors. The more pixels you have in a given space, the higher your photo's resolution. The pixel count for an 8 1/2-by-11-inch image depends entirely on the resolution.
Web-Quality Versus Print-Quality
The standard resolution for Web images is 72 ppi, or pixels per inch, which allows for the most detailed image possible on a computer monitor without "wasted" pixels. It's typically not of sufficient quality for print use as the grainy pixelation becomes obvious when printed. The optimal resolution for printed images is 300 ppi if your photograph is shot at the same size as you intend to print and higher if you plan to enlarge it.
Enlarging and Resolution Needs
A small image with high resolution may still not contain enough pixels to enlarge to a clear, crisp image. For example, if you have a 4-by-6-inch image with appropriate print quality of 300 ppi but you intend to enlarge it to twice its size, you might find that it still takes on a grainy appearance as it becomes larger. Starting at a higher resolution -- optimally, doubled at 600 ppi -- is much more effective in keeping the quality high.
8 1/2-by-11-Inch Image
An 8 1/2-by-11-inch image at a resolution of 72 ppi contains 484,704 total pixels. At 300 ppi resolution, the same size image contains 8,415,000 total pixels.
Digital Cameras and Megapixels Explained
Digital camera manufacturers use the term "megapixels" to describe the resolution at which their cameras are capable of taking clear photographs. Resolution on a computer or television is generally given in two dimensions, height and width in pixels. For example, a wide-screen computer monitor might display at a resolution of 1600 pixels by 1200 pixels. The digital camera manufacturer multiplies these two values to obtain the megapixel count. A camera capable of producing clear, precise photos at a resolution of 2,000 pixels by 1,500 pixels -- which, when multiplied, equals 3,000,000 total pixels -- would be advertised as a 3-megapixel camera.
Based in Tampa, Fla., Danielle Fernandez been writing, editing and illustrating all things technology, lifestyle and education since 1999. Her work has appeared in the Tampa Tribune, Working Mother magazine, and a variety of technical publications, including BICSI's "Telecommunications Distribution Methods Manual." Fernandez holds a bachelor's degree in English from the University of South Florida.