How many digital photos can a memory card store?

Unlike regular film, it's difficult to predict exactly how many photos you can fit on a flash card. The file size for one digital photo can depend on a number of factors:

Resolution: The higher the resolution, the bigger the file.
Compression: Your camera may give you the option of choosing a compression format (for example JPEG or TIFF) or taking uncompressed photos. Uncompressed files are the largest, and compression formats vary in size.
Colours: RGB photos (format for viewing on a monitor) are three times as big as black-and-white photos, and CMYK photos (format for printing) are four times as big as black and white.
Your camera model and the shooting conditions: Each camera gives slightly different results, and you may even get a different number of photos per card, depending on the subject you are shooting and light conditions.

The chart below can be used as a general guide: