The best way to read our size guide is to just go by the UK/US/EU size and remember there are no buttons or zips on the waist so you need to be able to pull them up over your thighs and bottom which is why the waist size is larger then the actual size.
These styles are stretch twill and have elastane running through them so if you are looking for a tighter fit these are the styles to go for as will allow easier pull up over your lower half. If you want them to be more fitted then go down a size. For example -
LESS BAGGY FIT
What the HECK is stretch twill?
Stretch Twill is a type of fabric with a pattern of diagonal parallel ribs.
There are fewer interlacings in twill as compared to other weaves which allows the yarns to move more freely, and therefore they are softer and more pliable. Twills also recover from creasing better than plain-weave fabrics do so less ironing needed.
Twills are durable, and is air- and water-resistant. Basically it's a thicker stretchy cotton, meaning you can move, bend and get them on and off easily. It is thinner then corduroy but easier to move in if you do a lot of running around.