What are megapixels?

Discover what your camera’s megapixel value means and how many megapixels you actually need

A megapixel is one million pixels, and pixels are the small squares that make up a photo. Therefore, a 12 megapixel camera will be able to capture 12 million pixels per inch to make up an image. Typically, the more pixels your camera can capture the better the resolution of your photo will be, as the more pixels that are squeezed into the frame, the better they blend together to create the image. When there are too few pixel, you can notice the edges of each square where they meet – just like a mosaic – creating a poor quality image.

The resolution of an image is measured in dots (or pixels) per inch. To work out how many pixels an image needs to be printed at good quality in a certain size, you just need to multiply the dots per inch by the image dimensions. For example, the optimum resolution for printing an image is 300dpi. If you wish to print an 8 x 10 inch photo, then multiply 300 by 8 and 10. This will show you that your image needs to be 2400 by 3000 pixels.

You can then work out how many megapixels you need to print a good quality 8 x 10 image, by multiplying these pixel dimensions together. 2400 multiplied by 3000 is 7,200,000 pixels, or 7.2 megapixels, so you will need a 7.2 megapixel camera to print good quality 8 x 10 inch photos.