adidas Originals Forum Mid RS fits in the same number as Air Force 1, Air Jordan 1, Air Max 90, Nike Dunk Low, Vans Old Skool, and Nike Blazer Mid '77 — essentially the full AF1/AJ1/AM90 baseline cluster. At offset +0.211, Forum Mid RS sits just below AJ1 (+0.217), rounding to "same" as both the AF1 cluster (0.000) and the AJ1/AM90 cluster in 0.5 increments. Based on 140 owner-reported pairs in the Feetlot database, only adidas YEEZY Boost 350 V2 and adidas Superstar run about half a size differently. If unsure: order true to size.
adidas Forum Mid RS Sizing — What 140 Pairs in the Feetlot Database Tell Us
The adidas Originals Forum Mid RS is among the most-tracked Forum variants in the Feetlot database. Across 140 owner-reported pairs, the residual variance is tight (standard deviation ≈ 0.25 size units). At offset +0.211, Forum Mid RS sits just below AJ1 (+0.217), rounding to "same" as AF1 (0.000), AJ1 (+0.217), AM90 (+0.314), Dunk Low (+0.275), Nike Blazer Mid '77 (+0.120), and Vans Old Skool (+0.165) at 0.5 increments. YEEZY Boost 350 V2 (+0.476) runs about half a size larger in number; adidas Superstar (−0.065) runs about half a size smaller in number than Forum Mid RS.
The Forum Mid RS leather upper and high-cut silhouette produce sizing consistent with the standard basketball-heritage sneaker cluster. Despite the high-top cut, the length offset aligns directly with AF1 Low, AJ1, and Dunk Low — the mid-top profile doesn't shift sizing relative to the low-cut baseline.
Should You Size Up or Down in adidas Forum Mid RS?
Standard fit (most people)
Order true to size — same as AF1, AJ1, AM90, Dunk Low, Blazer Mid, and Vans Old Skool. No adjustment needed from any of these.
Coming from adidas Superstar or adidas Stan Smith
Size up half. Superstar and Stan Smith run about half a size smaller in number than Forum Mid RS. If you wear Superstar in 9.5, take Forum Mid RS in 10.
Coming from YEEZY Boost 350 V2, YEEZY 380, or YEEZY 700 V3
Size down half. YEEZY 350 V2 and higher-offset models run about half a size larger in number than Forum Mid RS. If you wear YEEZY 350 in 10, take Forum Mid RS in 9.5.
Coming from Clarks Desert Boot or Red Wing Iron Ranger
Size up half to a full size. Heritage boots run smaller in number than Forum Mid RS.
How adidas Forum Mid RS Compares to Other Sneakers
The adidas Originals Forum Mid RS fits at the same numerical size as Nike Air Force 1, Air Jordan 1, Air Jordan 4, Nike Air Max 90, Air Max 97, Nike Dunk Low, Nike Dunk High, Nike Blazer Mid '77, Vans Authentic, Vans Old Skool, Reebok Club C, New Balance 574, and New Balance 990 V5. According to Feetlot data, all of these round to the same size in 0.5 increments.
The shoes that run larger in number than Forum Mid RS (size down half from those): adidas YEEZY Boost 350 V2, adidas YEEZY Boost 380, adidas YEEZY 700 V3, Nike Cortez, and Nike Free 3.0 V4. If you wear YEEZY 350 in 10, take Forum Mid RS in 9.5.
The shoes that run smaller in number than Forum Mid RS (size up half from those): adidas Superstar, adidas Stan Smith, adidas NMD R1 Primeknit, and Converse Chuck Taylor Ox/Hi. If you wear Superstar in 9.5, take Forum Mid RS in 10.
Sign in to Feetlot and add a few of your other sneakers to get a personal Forum Mid RS size recommendation.
adidas Originals Forum Mid RS Size Chart (US / EU / UK)
| US Men's | US Women's | UK | EU |
|---|---|---|---|
| 4 | 5 | 3.5 | 36 |
| 4.5 | 5.5 | 4 | 36.5 |
| 5 | 6 | 4.5 | 37.5 |
| 5.5 | 6.5 | 5 | 38 |
| 6 | 7 | 5.5 | 38.5 |
| 6.5 | 7.5 | 6 | 39 |
| 7 | 8 | 6.5 | 40 |
| 7.5 | 8.5 | 7 | 40.5 |
| 8 | 9 | 7.5 | 41.5 |
| 8.5 | 9.5 | 8 | 42 |
| 9 | 10 | 8.5 | 42.5 |
| 9.5 | 10.5 | 9 | 43 |
| 10 | 11 | 9.5 | 44 |
| 10.5 | 11.5 | 10 | 44.5 |
| 11 | 12 | 10.5 | 45 |
| 11.5 | 12.5 | 11 | 46 |
| 12 | 13 | 11.5 | 46.5 |
| 13 | 14 | 12.5 | 47.5 |
Common Sizing Mistakes
- Coming from Superstar and assuming Forum Mid RS fits the same. Superstar runs about half a size smaller in number than Forum Mid RS. If you wear Superstar in 9.5, take Forum Mid RS in 10.
- Carrying YEEZY 350 V2 sizing over directly. YEEZY 350 V2 runs about half a size larger in number. If you wear YEEZY 350 in 10, take Forum Mid RS in 9.5.
- Assuming the mid-top cut means different sizing than AF1 Low or Dunk Low. The collar height doesn't change length sizing. Forum Mid RS and AF1 Low round to the same size in the Feetlot model.
How Feetlot Computes These Numbers
Every adidas Forum Mid RS 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 its sizing drifts relative to a reference shoe (the Nike Air Force 1). The result: sizing advice that holds up no matter how unusual a wardrobe is.