Pick a shape, enter dimensions, set waste and your supplier rate the order quantity, bags, truckloads, and cost update live.
Slab length.
How many identical pours.
Your supplier's per-yard rate.
Labor (optional)
Order quantity
3.26
CU YDS
Bill of materials+10% waste
Ready-mix concrete
1 truckload short-load fee likely
Net 2.96 cu yd · Waste +0.3 cu yd
80-lb bags (alt.)
Net 133 bags · Waste +10%
60-lb bags (alt.)
Net 178 bags · Waste +10%
Cost projection
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Total · $537.78
3.26 cu yd
Volume = length × width × (thickness ÷ 12) gives cubic feet; divide by 27 for cubic yards the unit ready-mix is sold in.
Pick a shape, enter dimensions, set waste and your supplier rate the order quantity, bags, truckloads, and cost update live.
Order quantity = net yards × (1 + waste%). The 10–15% default covers spillage, over-excavation, and uneven subgrade.
An 80-lb bag yields ≈ 0.6 cu ft, so one cubic yard needs about 45 bags (60 for 60-lb bags). Counts round up suppliers don't split bags.
V = L × W × D ÷ 27 → +waste
Multiply length × width × (thickness ÷ 12), then divide by 27. A 20×12 ft slab at 4 in thick needs 2.96 yards net — order about 3.26 yards with 10% waste.
One cubic yard takes about 45 80-lb bags (0.6 cu ft each), and since bags aren't split the count rounds up. That 20×12 ft slab at 4 in needs roughly 147 bags with 10% waste.
Volume = length × width × (thickness ÷ 12) gives cubic feet; divide by 27, the number of cubic feet in a cubic yard — the unit ready-mix is sold in.
About 45 80-lb bags or 60 60-lb bags per cubic yard. An 80-lb bag yields roughly 0.6 cu ft.
Yes — add 10–15%. Order quantity = net yards × (1 + waste%) to cover spillage, over-excavation, and uneven subgrade. Loads under 4 yards usually trigger a short-load fee.
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