New Balance 991 Sizing Guide: True to Size? (49 Pairs)

New Balance 991 Sizing — What 49 Pairs in the Feetlot Database Tell Us

The New Balance 991 is tracked across 49 owner-reported pairs in the Feetlot database. The fit pattern across those owners is consistent: the typical wearer takes the same numerical size they wear in mainstream lifestyle sneakers, with residual variance roughly in line with the population-wide Feetlot figure of about 0.20 to 0.25 size units. The "true to size" advice that circulates on running and sneaker forums lines up with what Feetlot data shows for the average wearer.

The 991 is a premium running-heritage silhouette built on a supportive last with an ENCAP or similar cushioning midsole. The suede-and-mesh upper holds its shape and doesn't pack out lengthwise, so length stays faithful over the life of the shoe. The defining quirk is width: unlike most lifestyle sneakers that ship in a single width, the 991 is offered in narrow, standard D, and wide 2E and 4E options, which is why broad and slim feet rarely need to change the length number.

Should You Size Up or Down in New Balance 991?

Standard fit (most people)

Stay true to size. The 991 runs true in length for the average foot, and the standard D width suits a medium foot well. The structured upper and roomy toe box give a secure hold without pinching, so there is no reason to add or drop a half size for most wearers.

Wide feet

Stay true to size in length and choose the 2E or 4E width. This is the 991's biggest strength over single-width sneakers: instead of sizing up to chase width and ending up with too much length, wide-footed wearers keep their normal number and pick a wider last. If you can only find the standard D width, going up half a size adds a little room but is a worse fit than buying the correct width.

Narrow feet

Stay true to size and look for the B (narrow) width if available. The standard D width can feel slightly loose across the midfoot for genuinely narrow feet. The narrow width holds the foot without forcing you to size down in length, which would leave the toes cramped. Lacing snug also helps lock down a narrow foot in the standard width.

New Balance 991 vs 990 and other 99X models

The 991 shares length sizing with the 990, 992, and 993 family — pick the same number across the 99X line. Differences between those models come from midsole feel and last shape rather than length. If you already own a 990 or 992 that fits, take that same size in the 991.

How New Balance 991 Compares to Other Sneakers

The New Balance 991 sits very close in length to most lifestyle sneakers. According to Feetlot data, the 991 fits at essentially the same numerical size as the Nike Air Force 1, Air Jordan 1, Vans Authentic, Nike Air Max 90, Nike Blazer Mid '77, Air Jordan 4, adidas Superstar, Nike SB Dunk Low, and Nike Air Max 97. If a wearer takes size 10 in any of those, they take size 10 in the 991 too.

The notable exceptions where the numerical size shifts: the adidas YEEZY Boost 350 V2 runs about half a size smaller-fitting than the 991, so take half a size up in the YEEZY compared to your 991 number. The reverse is true for boot-style and broad-fitting casual models — the Converse Chuck Taylor and the Clarks Desert Boot both fit about half a size larger than the 991, so go half a size down from those numbers when buying the 991.

Sign in to Feetlot and add a few of your other sneakers to get a personalized New Balance 991 size recommendation calibrated to your actual foot rather than to the population average.

New Balance 991 Size Chart (US / EU / UK)

Common Sizing Mistakes

• Sizing up to get more width. The 991 comes in 2E and 4E widths — use them. Going up half a size for width gives you a shoe that's too long, with the foot sliding forward and the heel slipping.
• Assuming all New Balance run large. Some New Balance models run roomy, but the 991 fits true to size in length for most wearers, according to Feetlot data. Don't reflexively size down half just because it's a New Balance.
• Ignoring the width letter. A standard D 991 and a 2E 991 in the same number fit very differently. Always check the width code on the box, especially when buying the made-in-England versions.
• Buying small expecting break-in. The suede and mesh upper softens slightly but does not lengthen. A 991 that's too short stays too short.
• Treating the 991 like a Chuck Taylor or desert boot. Those run about half a size larger than the 991, so copying their number leaves the 991 too long.

How Feetlot Computes These Numbers

Every New Balance 991 sizing recommendation on Feetlot is the output of a global offset model fit to over 100,000 owner-reported shoe records. Each shoe gets a single number — its "size offset" — that captures how much its sizing drifts from the reference shoe (the Nike Air Force 1). When a Feetlot user provides their size in any tracked sneaker, the model recovers their true foot baseline and recommends the matching 991 size.

This works better than the more common pairwise approach because Feetlot uses the entire wardrobe graph. A YEEZY 350 owner contributes data about how YEEZY fits relative to Air Force 1 owners, which links to New Balance owners (many of whom own a Nike or adidas lifestyle shoe too), and so on. Even when two users share zero shoes directly, the chain of users in between transmits a consistent recommendation. The result: sizing advice that holds up no matter how unusual a wardrobe is.