Shoe Width Calculator

How the number is derived

Width is a girth, not a distance across. It is measured all the way around the foot at the ball, standing, with weight on it. The width letter is that girth expressed relative to the foot's length: the published scales step roughly three sixteenths of an inch of girth per letter, from AAA at the narrowest through to EEEE.

The reference point differs by scale. D is the standard men's width and B the standard women's, which is why the same letter means different things depending on which shoe you are looking at. A women's D is a wide shoe; a men's D is an ordinary one.

Because the letter is relative to length, the same girth produces a different letter on a different foot. A 24.5 cm girth is a standard D on a 27 cm foot and a wide fitting on a 25 cm one. Any width chart that lists girths without lengths is incomplete.

A worked example

A 270 mm foot with a 265 mm girth. The standard men's girth at that length is about 98% of the length, or 265 mm — so this foot is exactly a D.

Add 10 mm of girth and the same foot is around 275 mm, roughly two letters up the scale, an EE. That is a two-letter move from a single centimetre of girth, which is why width is worth measuring rather than guessing, and why people with wide feet find that going up in length never quite solves the problem.

Where the answer misleads

Sizing up in length to gain width is the usual workaround and it is a poor one. Length adds girth slowly, so you reach a shoe that is too long before you reach one that is wide enough, and the flex point of the sole ends up ahead of where the foot actually bends. That causes the crease across the toe box and the heel slip that people blame on the brand.

Feet also spread over time, and the change is mostly in width rather than length. Someone whose length has been stable for twenty years may well have moved two width letters through age, weight change or pregnancy. Remeasuring width is more informative than remeasuring length after the mid-twenties.

Finally, many shoes are simply not made in multiple widths. Where only one is offered it is usually a D for men and a B for women, so a wide foot in a single-width range is a fit compromise no calculator can resolve.