It is very important to find the correct size of shoe. There are two elements to shoe sizing: length and width. Shoe width is indicated by letters or by wide or medium. There is a difference between wide and medium shoes, and understanding that difference is essential to choosing the proper shoe.
Letters
Many shoes are not designated as either wide or medium. Instead, the shoe will be identified by a capital letter following the number that designates length--for example, 11D or 12E. It is necessary to know the letter system of a shoe chart to tell which letters are medium and which are wide.
Men's Shoes
The lettering system is different for men and women. A man's medium shoe is designated either as a C or D. A man's wide shoe carries the letters E or EE. The actual width of a shoe can vary from manufacturer, however. Not all size D or medium shoes will be exactly alike.
Women's Shoes
A women's medium shoe will be marked as a B. The letter D is used for a wide shoe. Thus, the letter D for a man is medium while it is wide for a woman. Like men's shoes, not every shoe will be identical. A medium shoe for one company may fit, but another company may require a wide for the same fit.
Medium or Wide
The difference between medium and wide shoes may not be that great but it is important. The correct size can be determined by the Brannock foot-measuring device. After a foot is placed on the device, it indicates what the proper width is for that foot. Even with this device, you need to try on shoes because they may not conform to the measurements.
Misconceptions
The perception you have about your foot width is irrelevant to shoe width. Medium and wide shoes are different for each manufacturer, so the only way to know if a medium or wide shoe is appropriate is to try the shoe on.