Chicken wire is OK for keeping chickens in ... but not keeping critters that like to eat chickens OUT! Chicken wire is very thin and easy to break, and only twisted together ... welding thicker wires together is much stronger.
Depending on where you plan to use it it ... for a run I'd suggest 1"X3" 14 gauge "welded wire" however tall you want ... for a coop ... 1/2" 19 gauge "hardware cloth" ...
Should be available at a farm/feed type store ... possibly a building supply store ... or hardware store ...
Call around ... buy once, cry once!