10×12 Shed Pad: Bags vs Ready-Mix
A small 10 by 12 ft shed pad where bagged concrete often beats the short-load fee.
Formula SSC-2026.1
Formula SSC-2026.1 · 3,000 PSI
Order volume
1.63 yd³
1.246 m³ placed+waste
Order weight
6,600 lb
2,994 kg
80 lb bags
74
2 pallets at 42 bags
60 lb bags
98
0.45 ft³ yield each
Rebar
174.00 ft
16 × 20 ft · 16 × 6 m · 72 lb
Ready-mix vs bags
$393.89
Truck $393.89 · 80 lb bags $499.50
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.
| Item | Net | Waste | Order | Unit price | Line total |
|---|---|---|---|---|---|
| Ready-mix concrete | 1.48 yd³ | 10% | 1.63 yd³ / 1.246 m³ | USD | $268.89 |
| Short-load fee | Under 4 yd³ | — | 1 truck @ 10 yd³ | USD | $125.00 |
| 80 lb pre-mix bags | 66.7 bags | 10% | 74 bags | USD | $499.50 |
| 60 lb pre-mix bags | 88.9 bags | 10% | 98 bags | USD | $529.20 |
| #3 rebar sticks, 20 ft | 16 sticks | 10% | 18 sticks / 16 × 6 m | USD | $153.00 |
| Rebar chairs | 63 crossings | 10% | 70 chairs | USD | $19.60 |
| Tie wire rolls | 63 ties | 10% | 1 rolls | USD | $8.00 |
Ready-mix truck
$393.89
0.16 nominal 10 yd³ loads · 1 to order
80 lb bags
$499.50
60 lb alternative $529.20 · delivery weight 6,600 lb
| Thickness | Order yd³ | Order m³ | 80 lb bags | Rebar ft | Ready-mix | 80 lb cost |
|---|---|---|---|---|---|---|
| 4 in | 1.63 | 1.246 | 74 | 191 | $393.89 | $499.50 |
| 5 in | 2.04 | 1.557 | 92 | 191 | $461.11 | $621.00 |
| 6 in | 2.44 | 1.869 | 110 | 191 | $528.33 | $742.50 |
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.
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Project: 10×12 Shed Pad: Bags vs Ready-Mix
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This sheet is an estimate for ordering and layout discussion. It is not a sealed design. Confirm the quantities with a licensed local professional and the authority having jurisdiction before you buy or build.
Engineering notes
Ten by twelve feet at 4 in is only about 1.48 cubic yards before waste, so a ready-mix truck is a short load. The calculator adds a suggested short-load fee under 4 yards and you can set that fee to the number your plant quoted, or to zero. Bag yield is 0.60 cubic feet for an 80 lb bag. Pallet count assumes 42 bags. A #3 grid at 18 in is the default because this is a light shed, not a shop slab.
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
- When do bags beat ready-mix on a shed pad?
- On pads under about 2 to 3 cubic yards the short-load fee often costs more than the extra bag price. Edit both prices and the fee to your local quotes.
- How many 80 lb bags are in a pallet?
- This sheet uses 42 bags per pallet as the planning count. Confirm the count printed on the pallet you actually buy.
- Should a shed pad have a thickened edge?
- A freestanding shed on a level pad often stays a uniform 4 in slab. Turn the thickened-edge control on if the shed plan shows a turned-down perimeter.