The general consensus on the sizing of Castelli clothing is that if you are used to UK sizing you need to go up 1 size because Castelli has 'Italian' sizing and has a performance cut so the clothing fits tightly. So to be sure of the size you need, the best thing to do is grab a measuring tape and compare against the size charts below.
If the Castelli product is listed as a 'Womens' product then use the Womens Size Guide, otherwise use the Mens Size Guide.
Castelli Mens Tights and Shorts Sizing Guide
| ||Small ||Medium ||Large ||X-Large ||XX-Large ||XXX-Large |
|Waist ||80cm / 31.5 inches ||84cm / 33 inches ||88cm / 34.5 inches ||93cm / 36 inches ||99cm / 38 inches ||103cm / 40 inches |
|Hips ||94cm / 37 inches ||98cm / 38.5cm ||102cm / 40 inches ||107cm / 42 inches ||112cm / 44 inches ||117cm / 46 inches |
|Inseam ||81cm / 31.8 inches ||82cm / 32.2 inches ||83cm / 32.6 inches ||84cm / 33 inches ||85cm / 33.4 inches ||86cm / 34 inches |
Castelli Womens Tights and Shorts Sizing Guide
| ||X-Small ||Small ||Medium ||Large ||X-Large |
|Waist ||63cm / 25 inches ||68cm / 26.5 inches ||73cm / 28.5 inches ||78cm / 30.5 inches ||83cm / 32.5 inches |
|Hips ||87cm / 34 inches ||92cm / 36 inches ||97cm / 38 inches ||102cm / 40 inches ||107cm / 42 inches |
|Inseam ||75cm / 29.5 inches ||76cm / 30 inches ||77cm / 30.5 inches ||78cm / 30.5 inches ||79cm / 31inches |