For most people the Air Max 90 runs true to size. Take your usual Nike size. It is one of the more predictable silhouettes in the range, which is part of why it has survived since 1990 without needing to be explained.
The caveats worth knowing
Three things move the answer.
Width. The 90 is built on a fairly standard last but the toe box is not generous. A genuinely wide foot will feel the sidewalls before it feels the length. Sizing up half solves width poorly and length badly, so if you are wide, expect a firm fit rather than a roomy one.
Socks. The 90 is a shoe people wear with thicker socks more often than they admit. If that is you, half a size up is reasonable.
What you are coming from. If your reference point is the Air Force 1, note that the AF1 runs notably large. People who take a half size down in AF1 usually take their true size in the 90.
How it compares
| Model | Commonly reported fit | Toe box |
|---|---|---|
| Air Max 90 | True to size | Moderate |
| Air Force 1 | Runs large, many size down half | Roomy |
| Vomero 5 | True to size, snug midfoot | Narrow |
These are widely reported tendencies rather than manufacturer specifications. Feet vary more than shoes do.
If you are between sizes
Go up, not down. The 90 has a structured heel and a firm midsole, and a shoe that is marginally long is a far smaller problem than one that is marginally short. There is no meaningful break-in that adds length.
Frequently asked questions
Should I size up in Air Max 90?
Only if you have a wide foot, wear thick socks, or sit between sizes. Otherwise take your usual size.
Do Air Max 90 fit the same as Air Force 1?
No. The Air Force 1 is widely reported to run large, and many wearers take half a size down in it. The Air Max 90 is closer to true to size, so the two often differ by half a size for the same person.
Are Air Max 90 good for wide feet?
Not especially. The toe box is moderate rather than generous. Sizing up adds length before it adds width, so it is an imperfect fix.
Do Air Max 90 stretch over time?
The upper softens with wear, which eases pressure across the width. They do not get longer. Do not buy short and hope.