I used to dismiss the idea of a tool belt .... until I had one. They make a lot of sense for jobs around the garden - when you need multiple items to hand. Just load up with the tools you might need and save yourself the endless trips back and forth to the shed or greenhouse.
These are sized with the American workwear market in mind so
S/M - from a 28" waist up to a 34/36"
L/XL - from 34" up to around a 44" waist
Edd: I'm around a 35" waist - sometimes I can wear 34" jeans, sometimes a 36". I wear a 36" in the Carhartt Bib Overalls. I can wear both sizes of the tool belt - the S/M at its maximum length and the L/XL at its smallest. I've chosen to go with the S/M as I personally prefer not to have the excess strap on the L/XL
Lou: I'm a size 10-12 (29" waist) and I wear the S/M.
Material: the toolbelt is made from Carhartt's legendary 12oz, firm hand, 100% ring spun cotton duck canvas. This means that when new the fabric feels stiff, but with time and wear develops its own shape to fit your body.
Pocket situation: it has four large pockets and one small pocket, a pencil pocket (or penknife pocket) and two tool loops.
The strap is adjustable with a strong clip to fasten.
If you want to, as it's cotton canvas, it can easily be made waterproof by applying Otter Wax Fabric Wax