Yet another example of the confusion when people try to apply SI-prefixes to the binary system..... In short, it depends on who you talk to or what you read. Some places will do the power-of-ten conversion and say that a megapixel is 1,000,000 pixels, others will take the binary conversion and say that a megapixel is 1048576 (ie 1024*1024) pixels. Same thing goes for hard-drives etc, it was simplified to normal powers of ten some time ago to make marketing easier - a 1-gigabyte hard drive will be 1,000,000,000 bytes, but if you look at technical uses (ie file sizes etc), 1 gigabyte is 1,073,741,824 bytes. Since kilo/mega/giga etc are all SI-prefixes, they technically refer to power-of-ten orders of magnitude (ie thousand, million, billion etc). Since computers etc run in the binary system (power-of-two) To get around this confusion they changed the prefix system to kibi/mebi/gibi (ie 1024, 1048567, 1073741824). Most end-users will never see those terms used though, and will just keep using kilo/mega/giga etc interchangeably (even when it is technically wrong). As an example, my 10MP (advertised) Panasonic FZ28 bridge camera produces 3648 x 2736 pixel photos, which equates to 9980928 pixels, which is much closer to 10,000,000 (10 megapixels) than it is to 10737418240 (10 Mebipixels) As an aside, the camera world is rife with confusion and myth/hype in refernce to the two numbers commonly used to market them - megapixels and zoom. For instance, you actually have to QUADRUPLE the megapixel rating to get a doubling of resolution (or picture area), and zoom ratings (ignoring digital zoom for now) are actually the multiplication of the focal length.