When you work with digital images, you may wish to know how to calculate the file sizes of the images. Estimating file sizes of the images helps you plan ahead in terms of media, archival disks and RAM memory needed. For example, for an image that is 640 x 480 pixels with a 24-bit color depth, multiply 640 x 480 x 16 = 7,372,800 bits. To convert to bytes, that figure must be divided by 8, which equals 921,600. To convert to KB, divide the number of bytes by 1024, which equals 900 KB. Larger sizes can be converted to megabytes (MB) by dividing the number of KB by 1024. For example, a 6-inch x 8-inch photo with 300 DPI is calculated by multiplying 6 X 300 and 8 x 300, which equals 1800 x 2400 pixels. Writer Bio
