Guide
Bags vs a ready-mix truck
The estimate shows both a yardage and a bag count so you can see the scale. It does not choose the path. Calling a ready-mix plant is not the same as buying bags at the store. This page names the difference. It does not place an order.
What the two numbers are
Cubic yards are the volume of the rectangle you measured. The bags calculator then divides that volume by the yield printed on a typical bag and rounds up. Fifty-six bags of 80 lb mix for a 10×10 patio at 4 inches is arithmetic, not a shopping cart.
Ready-mix is sold by the yard, often in quarter-yard steps, sometimes with a minimum load. Those steps belong to the plant. The calculator will not invent them.
A useful starting band, not a rule
Under about 1 cubic yard, bags are often easier: you can stage the work, and a truck minimum may cost more than the extra bags. Between 1 and 3 yards, either path can make sense. Past that, most home pours go on a truck unless you have a reason to stay with bags.
Weight still matters on the bag path. Fifty-six 80 lb bags are 4,480 lb before you add water. The bags tool shows that total. A pickup is not a certified scale.
Bags and ready-mix are not the same product
A bag lists a yield and a mix. A dispatcher asks about slump, air, access, and unload time. Do not treat a bag count as a substitute for a mix written on a plan. Do not treat a planning yardage as a load that is already on the way. What to tell a ready-mix plant is the list to have in front of you if you call.
Pour Plan does not sell bags and does not dispatch trucks. Confirm the yield on the bag in your hand and the minimum at the plant you actually use.