How to Calculate Pixels
A digital camera or video camera's resolution is measured in pixels. A pixel represents one dot of color on your computer's screen, and the amount of pixels in an image is a good indicator of how large the image or video is. Consumer digital cameras are measured in megapixels, a measurement that is important in terms of image quality and cropping. Knowing how many megapixels a camera has is a good starting point to determine how large an image you can print or how to crop it to a desired size. Calculating megapixels is simple and easy to do.
Locate the image for which you want to calculate the number of pixels.
Right-click on the image and select "Properties" from the resulting menu.
Click the "Details" tab and scroll to the "Image" header.
Make a note of the numbers in the "Width" and "Height" fields.
Run your calculator program and multiply the two numbers together. The resulting number is the amount of pixels you have. One million pixels is equal to one megapixel.