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Length imperial. Weight lb. Currency USD. Weight uses 1 lb = 0.45359237 kg. Currency converts US-dollar planning prices and does not change volumes, counts, or geometry.

12×40 Driveway: Ready-Mix vs Bagged Delivery

The 12 by 40 ft driveway again, this time as a haul choice between a truck and pallets.

Formula SSC-2026.1

Formula SSC-2026.1 · 4,000 PSI

Order volume

8.15 yd³

6.230 m³ placed+waste

Order weight

33,000 lb

14,969 kg

80 lb bags

367

9 pallets at 42 bags

60 lb bags

489

0.45 ft³ yield each

Rebar

684.00 ft

45 × 20 ft · 54 × 6 m · 503 lb

Ready-mix vs bags

$1,344.44

Truck $1,344.44 · 80 lb bags $2,477.25

Slab footprint and rebar gridLive scaled blueprint
40.00 ft12.00 ft#4 / 12 mm at 18 in OC · 5 in slab

Grid lines are equalized so the drawing stays readable. The order count uses on-center spacing with a bar at each end of the layout, then holds concrete cover in the field.

Bill of materials and shopping list
ItemNetWasteOrderUnit priceLine total
Ready-mix concrete7.41 yd³10%8.15 yd³ / 6.230 m³USD$1,344.44
Short-load feeFull load—1 truck @ 10 yd³USD$0.00
80 lb pre-mix bags333.3 bags10%367 bagsUSD$2,477.25
60 lb pre-mix bags444.4 bags10%489 bagsUSD$2,640.60
#4 rebar sticks, 20 ft45 sticks10%50 sticks / 54 × 6 mUSD$700.00
Rebar chairs243 crossings10%268 chairsUSD$75.04
Tie wire rolls243 ties10%1 rollsUSD$8.00

Ready-mix truck

$1,344.44

0.81 nominal 10 yd³ loads · 1 to order

80 lb bags

$2,477.25

60 lb alternative $2,640.60 · delivery weight 33,000 lb

Side-by-side thickness comparison at the same footprint
ThicknessOrder yd³Order m³80 lb bagsRebar ftReady-mix80 lb cost
4 in6.524.984294752$1,075.56$1,984.50
5 in8.156.230367752$1,344.44$2,477.25
6 in9.787.476440752$1,613.33$2,970.00
Show the deterministic formula

Slab ft³ = L × W × thickness ÷ 12. Thickened-edge extra = footing band × (footing depth − slab thickness), with corner squares counted once.

yd³ = ft³ ÷ 27. m³ = ft³ × 0.0283168. Weight uses 150 lb/ft³, then the header converts that pound total at 1 lb = 0.45359237 kg. 80 lb bags yield 0.6 ft³ and 60 lb bags yield 0.45 ft³. Currency changes the price labels only.

Bars across a span = floor(span ÷ spacing) + 1. Order sticks = that count, plus 10, 5, or 15 percent waste, cut from 20 ft and 6 m stock. Chairs = one per grid intersection.

Engineering notes

At 5 in and 10 percent waste this driveway is several cubic yards, so the bag count is large and the ready-mix truck is the usual winner unless the truck cannot reach the apron. Read both costs with your prices, then read the order weight if a pump or a buggy is required. The thickness table still shows 4, 5, and 6 in. PSI is 4,000. The grid is #4 at 18 in.

Code reference

IRC R506.1 sets a 3.5 in minimum for concrete slab-on-ground floors. Reinforcement cover and spacing follow ACI 318 practice and the local inspector. This quantity takeoff is not a soils or structural design.

Field questions

How do I tell which delivery is cheaper?
The two summary cards highlight the lower of ready-mix-plus-fee and the 80 lb bag total, using the prices you type.
What if the truck cannot reach the forms?
The cheaper material can still be the wrong delivery. The weight and the yards are there so you can price a pump or a bag relay separately.
Does the driveway preset match the masonry page?
The footprint matches the 12 by 40 ft driveway. This URL is the freight reading of that takeoff, with the same live calculator.