adidas Originals Marathon 88 Sizing: Run Big or Small?

adidas Marathon 88 Sizing, What the Feetlot Database Tells Us

The adidas Originals Marathon 88 is a faithful reissue of a late-1980s running silhouette, and its sizing reflects that heritage: clean, predictable, and close to a classic court last. Based on 46 verified pairs in the Feetlot database, the Marathon 88 lands essentially on the Nike Air Force 1 baseline, drifting only a touch toward the snug side. In plain terms, it runs true to size, the half-size-up chatter you sometimes hear about retro runners does not show up strongly here.

Feetlot's offset model places the Marathon 88 just barely on the small side of the Air Force 1, which is well within true-to-size territory. For the average foot, the size printed on the box is the size to buy.

Should You Size Up or Down in adidas Marathon 88?

Standard fit (most people)

Buy true to size. The suede-and-mesh upper wraps the midfoot cleanly, and the toe box is moderate rather than roomy. A true-to-size pair gives a secure lockdown without pinching, and the upper relaxes slightly over the first few wears.

Wide feet

Consider rounding up half a size. The Marathon 88 last is on the standard-to-slightly-narrow side through the forefoot, so wider feet gain noticeable comfort from the extra half size, at the cost of a little extra length.

Narrow feet

Stay true to size. The lace-up suede upper cinches down well over a slimmer foot, and the heel holds securely without slip. There is rarely a reason to size down in the Marathon 88.

In-between sizes and thick socks

Because the Marathon 88 reads a hair snug rather than generous, anyone who falls between two sizes, or who plans to wear thicker socks, is better off rounding up to the larger of the two. For a thin-sock, everyday fit, the smaller size still works.

How adidas Marathon 88 Compares to Other Sneakers

According to Feetlot data, the Marathon 88 fits almost identically to the Air Force 1, take the same size in both. It also lines up closely with the Nike Dunk Low, where owners who have both tend to keep the same size.

Against the canvas classics, the Marathon 88 runs a little smaller: owners who have both the Marathon 88 and a Converse Chuck Taylor, whether the low Core Ox or the Hi, tend to take a slightly larger number in the Marathon 88. The same goes for the Clarks Desert Boot, where Marathon 88 wearers generally land about half a size up from their Clarks size.

Going the other direction, the Marathon 88 runs a touch larger than a few notoriously slim adidas lasts. Owners who have both it and the adidas Copa Mundial, a famously tight football boot, tend to take a smaller number in the Marathon 88, and it also runs marginally larger than the New Balance 574. In short, the Marathon 88 sits right in the middle of the lifestyle-sneaker pack.

Sign in to Feetlot and add a few of the shoes already owned to get a personal Marathon 88 size recommendation calibrated to a real foot.

adidas Marathon 88 Size Chart (US / UK / EU)

Common Sizing Mistakes

• Sizing up out of habit. Retro runners have a reputation for running small, but Feetlot data shows the Marathon 88 fits true to size, an unnecessary size up leaves the heel loose.
• Sizing down for a "sleek" look. The Marathon 88 already reads slightly snug; going down often cramps the toes without improving the silhouette.
• Ignoring foot width. The forefoot is standard-to-narrow. Wide feet should round up half a size rather than forcing a true-to-size pair.
• Assuming it matches your Converse size. Chuck Taylors run smaller in number, most wearers take a slightly larger size in the Marathon 88.

How Feetlot Computes These Numbers

Every adidas Marathon 88 sizing recommendation on Feetlot is the output of a global offset model fit to over 100,000 verified 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 shoe, the model recovers their true foot baseline and recommends the matching Marathon 88 size. This works better than a simple pairwise lookup because Feetlot uses the entire wardrobe graph: even when two users share no shoes directly, the chain of users between them transmits a consistent recommendation. That is why a shoe with a modest number of direct owners still gets a stable size estimate.