Measure waist at the height pants are normally worn, and keep tape comfortably loose.
S - Waist 24-26 Inseam 29
M - Waist 28-29 Inseam 29.5
L - Waist 30-31 Inseam 30
XL - Waist 32-33 Inseam 30.5
2XL- Waist 36-37 Inseam 31