Concrete calculator
A slab's volume in cubic yards (how ready-mix is ordered) and the bags of pre-mix it would take, from length, width, and thickness, with an over-order allowance.
Concrete needed1.36 cu ydwith the 10% allowance
Raw volume33.3 cu ft · 1.23 cu yd
Bags of pre-mix62 bags
Bag cost$372.00
Bagged mix suits small pours (footings, posts, a small pad). For anything over about a cubic yard, ready-mix delivery is usually cheaper and faster, ordered by the cubic yard above.