Depending on the degree of maximum compression exerted (at the heel), you can subdivide socks into compression classes. The international reference standard RAL GZ 387 provides the following subdivision:
| Classes | Type of compression | Compression exerted on the ankle |
|---|---|---|
| CLASS 1 | Lightweight | 18-21 mmHg |
| CLASS 2 | Moderate | 23-32 mmHg |
| CLASS 3 | Strong | 34-46 mmHg |
| CLASS 4 | Extra strong | 49 mmHg e sup. |