What D, E, and EE Actually Mean: Width Fittings vs. Shoe Volume

Width letters — AAA, B, D, EE, and the rest — look like an arbitrary code until you know what's actually behind them. They're not a separate, mysterious sizing system; they're a straightforward ratio between two measurements you can take yourself with a tape measure, mapped onto a nine-step scale. Once the mechanism is clear, "I need a D" or "I'm probably a B" stops being guesswork and becomes a number you can actually calculate.

The ratio behind every width letter

Footwear fitting uses the girth around the ball of the foot — its widest point, at the base of the toes — expressed as a percentage of foot length, not as an absolute measurement in centimetres. That's the key idea: a wide-looking foot on a person with small feet and a narrow-looking foot on a person with large feet can land on the exact same width letter, because what matters is the ratio between girth and length, not either number by itself. The nine-letter scale runs from AAA (narrowest, around 28% of foot length) up through AA, A, B, C, D, E, EE, to EEE (widest, around 43%), in steps of about 1.875 percentage points each. D sits at almost exactly 37.5% and is the conventional standard, medium width for men's shoes; B sits at almost exactly 33.75% and is the conventional standard for women's shoes.

A worked example, two ways

Take a foot measuring 27cm long with a 10.5cm ball-of-foot girth. Divide 10.5 by 27 and multiply by 100, and you get a ratio of about 38.9% — just past the 37.5% mark for D, which places this foot at an E, a half-step wider than standard men's medium. Compare that with a shorter, narrower foot: 24cm long with an 8.6cm girth, which works out to roughly 35.8% — between B and C, landing at C. Notice that the second foot's girth (8.6cm) is smaller in absolute terms than the first's, which might suggest "narrower," but the ratio is what actually gets classified: an 8.6cm girth on a 24cm foot is proportionally wider relative to that foot's own length than a much larger girth would be on a longer foot. Width is inherently a relative measurement, not an absolute one.

Measuring your own ball girth correctly

Wrap a flexible tape measure (a fabric sewing tape works better than a rigid one) around the widest part of your foot, at the base of the toes where they meet the rest of the foot, while standing with your weight evenly distributed across both feet. Keep the tape snug against the skin without compressing the foot — pulled too tight, the measurement reads narrower than the foot actually is; left loose, it reads wider. Measure both feet, since one is very often somewhat wider than the other, and use the larger figure as your reference width when shopping. Pair it with a length measurement taken the same way you would for a size conversion, and you have both numbers the ratio needs.

Width is not the same thing as overall volume

This is the distinction that trips up the most people: width, as measured and classified here, describes only the horizontal spread at one specific point — the ball of the foot. It says nothing about the volume of the shoe over the instep, through the toe box height, or around the heel, all of which contribute to how "roomy" a shoe feels but aren't captured by the width letter at all. Two shoes can share an identical width letter and still fit very differently if one has a low-volume, close-fitting instep design and the other has a higher-volume, more generous cut through the same width. This is why a width letter narrows down the search but doesn't guarantee fit on its own — it's solving for one specific dimension, not the whole three-dimensional shape of the shoe.

In practice, this means a foot with a high instep or a particularly tall arch might need to size up in overall volume (sometimes by trying a style described as having a "roomier" or "relaxed" fit) even when the ball-of-foot width letter comes out as standard. Conversely, a low-volume foot can end up swimming in a shoe that's technically the correct width and length if the shoe's overall cut runs generously. Width and volume are related but genuinely separate problems, and a width calculator only ever solves the first one.

Why most shoes only come in one or two widths

Manufacturing a shoe in every width letter across every size multiplies the number of unique molds and production runs considerably, which is expensive, so most mass-market footwear is only produced in medium (D for men's, B for women's), sometimes with a single "wide" option added. If your calculated width sits well away from the middle of the scale — a narrow AA or A, or a wide EE or EEE — expect a smaller pool of brands and styles to choose from, and specifically look for brands that advertise multiple width options rather than assuming any retailer stocks your size across the full letter range.

Why sizing up in length doesn't fix a width problem

A common workaround for a too-narrow shoe is buying a longer size, on the theory that a bigger shoe overall will have more room everywhere. It's a poor substitute for an actual width fix. Going up a length size does add a small amount of width at the ball of the foot, since the whole shoe scales up together, but it adds noticeably more length — extra room at the toe you didn't need — while barely denting a genuine width shortfall. The result is a shoe that's now too long, with a heel that slips because there's dead space at the front, while still pinching across the ball of the foot because the width increase per size step is proportionally much smaller than the length increase. If the actual problem is width, the fix is a wider letter in your correct length, not a longer shoe in the same width.

Signs the problem is width, not length

A handful of fit complaints point specifically at width rather than length, and recognizing the pattern saves a round of guessing:

• Pressure or bulging across the widest part of the foot while the toes have plenty of room lengthwise — classic too-narrow signal.
• The upper visibly straining or the stitching under stress at the ball of the foot, even in a size that measures correctly for length.
• Persistent side-of-foot rubbing at the same spot, rather than a toe-area or heel-area complaint.
• A shoe that feels fine standing still but tightens uncomfortably once your foot naturally spreads under load while walking — feet widen slightly with weight-bearing, and a borderline width letter often only becomes noticeable in motion.

None of these are diagnostic on their own, but two or three together are a good reason to actually measure ball girth rather than continuing to experiment with different lengths.

Width availability varies a lot by shoe category

Not every category of shoe treats width the same way. Athletic and running shoes, built on more forgiving synthetic and mesh uppers, often flex enough that a half-step-off width letter goes unnoticed, and many athletic brands offer at least a wide option specifically because running-shoe fit complaints skew heavily toward width. Formal leather dress shoes are the opposite: less forgiving material, more precise lasts, and width options are less commonly stocked outside of brands that specifically market fit range as a feature. Boots sit in between — leather uppers that eventually give a little with break-in, but usually only one or two width options if any. Knowing which category you're shopping in sets realistic expectations for how much a slightly-off width letter will actually matter in practice, and how likely you are to find your exact letter in stock at all.

Width can differ between your two feet

Just as with length, it's common for one foot to measure a half-letter or more wider than the other, and the same rule applies: buy to fit the wider foot, and manage any looseness on the narrower side with a thicker sock, a heel grip, or an insole rather than sizing down and accepting pressure on the wider foot. Measuring both feet rather than assuming they match is a small extra step that avoids buying a width that's only correct for one side.

Checking your number against a full table

The full width scale, with the exact percentage band for every letter from AAA to EEE, is laid out on the Shoe Size & Width Reference page, generated from the same classification logic described here. If you've measured your own foot length and ball girth, the Width & Fit Guide calculator takes both figures directly and returns your specific letter without you needing to do the percentage math by hand.

The bottom line

A width letter is nothing more mysterious than a ball-girth-to-length ratio mapped onto a nine-step scale, which is exactly why the same letter can describe a small foot and a large one equally well. Measuring correctly — both feet, weight evenly distributed, the larger figure used as your reference — gets you a real number to shop against instead of a guess. Just remember that the letter answers one specific question about your foot's shape, not the whole picture: a shoe with the right width letter can still feel wrong if its overall volume doesn't suit your foot, which is a separate fit dimension worth paying attention to once width is settled. Measure once, write both numbers down, and you'll have a reliable reference for every future purchase rather than a fresh guess each time.