The smallest format with 120 film is 6cm x 4.5cm and is refereed to as the "Ideal Format" because its ratio is the same as that of 4x5 film and 10x8 film all of which fit neatly on to 10 x 8 paper; there is no wastage. Because the frame size is small, there are 16 exposures with this format. Here the longer length of the format is running across the film, and the width runs down the length of the film.

The next size is 6X6 and this is quite different than all the other photographic formats in that it forms a square which some photographers find a challenge to use. There are 12 exposures with this format. As the 6x6cm format covers over four times the film area of a 35mm frame there is a corresponding increase in the quality of the image. Many photographers will use this format and crop to obtain a rectangle.

Slightly larger than this is 6x7cm and there are 10 exposures with this format. This format takes the squareness out of the 6x6cm size and has the longer length of the format running down the length of the film.
 

The largest common format with this size film is 6x9 and there are only 8 exposures with this size. Here the ratio is 2:3 and besides using larger areas of film which gives maximum quality with 120 film, it has a more definite rectangular shape than 6x7.

There are also special  Panoramic cameras.that use 120 film and have a 6 x 12 cm format.

Some camera systems allow the use of 220 film, which has the same width as 120, but as it has no paper backing, only a small leader and trailer, the length of film is twice as long and allows double the exposures in all of the cases above.