OS1st Size Guide - Plantar Fasciitis Socks
| Small | Medium | Large | X-Large | |
| US (Men's) | 3-5.5 | 6-9.5 | 10-13 | 13+ |
| US (Women's) | 4-6.5 | 7-10.5 | 11+ |
| Small | Medium | Large | X-Large | |
| US (Men's) | 3-5.5 | 6-9.5 | 10-13 | 13+ |
| US (Women's) | 4-6.5 | 7-10.5 | 11+ |