In general, knee warmer size should be the same as your bib short size. However, since bib fit & cuts vary please verify size with our sizing chart.
If you are between sizes we recommend sizing down as the fabric has a fair amount of stretch
Small - Thigh: < 21in, Inseam < 31 in
Medium - Thigh: 21 - 24 in, Inseam 32 - 34 in
Large - Thigh: 24 + in, Inseam 34 + in