Digital photo quality is measured in megapixels. A pixel is a tiny dot of color, and when many pixels are combined an image is composed: 1 megapixel equals 1 million pixels. In 1999, when the digital camera industry began to boom, the standard digital camera took photos made up of between 1 and 2 megapixels. Today, most newly released digital cameras take photographs with 10 megapixels or more. If your camera is capable of taking photos of at least 4 megapixels, then you can determine the number of megapixels in a specific image using a simple calculation.
Determine the length and width of the digital photograph in terms of pixels. You may find this information by right-clicking the image and selecting the "Get Info" box or by examining the photograph in a photography software program. As an example, let's consider a photograph that is 1,000 pixels in length and 2,000 pixels in height.
Multiply the length of the photograph in pixels by the height of the photograph in pixels. In the example, you would multiply 1,000 by 2,000.
Consider the product of your calculation. If your product is between 4 million and 5 million pixels, then your photo is considered to be 4 megapixels. If the result of your calculation is less than 4 million pixels, than your photo is smaller than 4 megapixels. If the result is larger, your photo is larger than 4 megapixels. In the example, the product is 2 million pixels or 2 megapixels, which is smaller than 4 megapixels.
Most digital cameras have a marking on the shell indicating the maximum number of megapixels in a photo taken with that camera. If you find that your digital camera is rated for 3 megapixels or below, you know that you will not be able to take a 4-megapixel photograph.