10x12 Concrete Slab, 4 Inches Thick
Poured 4 in thick, a 10 × 12 ft slab covering 120 sq ft needs about 1.63 cubic yards of concrete once 10% is added for waste. For ready-mix, order 1.75 cu yd for the 10x12, about $305 – $425 delivered, short-load fee included. Bagged, the same 10x12 is 74 80 lb or 98 60 lb bags, about $490 – $686 for the concrete alone.
- Ready-mix order
- 1.75 cu yd
- Ready-mix cost
- $305 – $425
- 80 lb bags
- 74
- Bag cost
- $490 – $686
The 10x12 (4 in) prices are national material ranges as of 2026-09, not a quote from a supplier.
Typical uses for a 10x12 pad
At 120 sq ft, a 10x12 slab sits exactly at the most common permit-exemption size for sheds, which is why so many shed kits are sold at this footprint.
As a patio it fits a rectangular six-seat dining table, or a smaller table plus a grill on the 12 ft side, without crowding the walkway past it.
If the shed is going to hold a riding mower or a workbench, a 10x12 gives room for both, with the door on the 12 ft wall for a straighter path in.
Before you pour the 10x12 at 4 in
- Confirm whether your town measures the 120 sq ft limit at the floor or at the roof overhang before buying the kit.
- Put the shed door on the side that faces the yard path, then add a short ramp or flush apron there.
- Keep the pad at least a few inches above grade on the uphill side.
Full plan for a 10x12 slab, 4 in
- Area
- 120 sq ft
- Thickness
- 4 in
- Volume
- 1.63 cu yd
Bagged concrete estimate (DIY)
$606 – $875
Est. as of 2026-09 — not a live quote
Ready-mix delivered, incl. short-load fee (materials only)
$305 – $425
Est. as of 2026-09 — not a live quote
For a pour this size, ready-mix delivery is typically more practical than mixing bags by hand.
Shopping list
- Concrete mix (60 lb bags) Or 147 × 40 lb, 118 × 50 lb or 74 × 80 lb bags. 98 bags
- Ready-mix concrete Alternative to bagged mix; most suppliers have a 1 cu yd order minimum. 1.75 cu yd
- Compactable gravel sub-base 4 in compacted base beneath the slab. 2 tons
- 6x6 welded wire mesh Reinforcement for crack control; not a substitute for engineered rebar on structural slabs. 132 sq ft
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Buy bagged concrete
Pick up bagged mix and reinforcement from a hardware store for smaller pours.
View shopping listAssumptions
- Waste allowance: 10% applied to account for over-excavation and spillage.
- Approx. wet weight: 6,600 lb (3.3 tons).
- Prices are national-average retail/delivery ranges as of 2026-09, not live quotes.
- Ready-mix orders under 10 cu yd usually carry a short-load fee; the ready-mix range includes a flat $60-$110. Some suppliers charge per yard instead, so ask for the full fee schedule.
Bags or ready-mix for a 10x12 slab, 4 in?
A 10x12 at 4 in lands in the 1 to 3 cubic yard range, where bags and ready-mix cost about the same. For the 10x12, 74 80 lb bags cost about $490 – $686, while 1.75 cu yd of ready-mix costs about $305 – $425, short-load fee included. On the 10x12, ready-mix comes out cheaper by about $223 at the middle of each range, and it saves mixing 74 bags.
Is 4 in thick enough for a 10x12 slab?
4 in is the usual thickness for a 10x12 patio, walkway, shed floor or equipment pad that carries foot traffic.
Control joints for a 10x12 slab at 4 in
A 10x12 slab at 4 in shrinks as it cures, and without joints it cracks wherever it chooses. The usual rule (ACI and PCA guidance) puts joints in a 10x12 at 4 in every 8 to 12 ft, 24 to 36 times the thickness, cut 1 in deep (a quarter of the thickness) as soon as the surface takes the saw without raveling, usually within the first day.
On the 10x12 at 4 in, a joint every 10 ft or less means 1 joint across the 12 ft side and 1 joint across the 10 ft side: 4 panels of about 6 × 5 ft and 22 ft of saw cut. For the 10x12 that's more joints than the spacing alone calls for, so that no panel is more than 1.5 times as long as it is wide.
How much a 10x12 slab 4 in thick weighs
At roughly 150 lb per cubic foot of wet concrete, a 10x12 at 4 in puts about 6,600 lb (3.3 tons) on the ground. As bags, the 10x12 is 74 80 lb bags, 5,920 lb in all: about 4 trips in a pickup carrying 1,500 lb a load. For that many trips with the 10x12, check the payload on your truck's door-jamb sticker, or have the store deliver the pallets for a fee.
The 10x12 at 4 in against nearby sizes
Every row uses the same 10% waste and prices as the 10x12 at 4 in; costs are for the concrete only.
| Slab | Cu yd | 60 lb bags | 80 lb bags | Ready-mix order | Bags cost | Ready-mix cost |
|---|---|---|---|---|---|---|
| 10x10 slab, 4 in | 1.36 | 82 | 62 | 1.5 cu yd | $410 – $574 | $270 – $380 |
| 10x12 slab, 4 in (this page) | 1.63 | 98 | 74 | 1.75 cu yd | $490 – $686 | $305 – $425 |
| 12x12 slab, 4 in | 1.96 | 118 | 88 | 2 cu yd | $590 – $826 | $340 – $470 |
Questions about a 10x12 slab, 4 in
How many bags of concrete for a 10x12 slab 4 inches thick?
A 10x12 slab at 4 in takes about 74 80 lb bags or 98 60 lb bags (or 118 50 lb, 147 40 lb), with 10% added for waste: 44 cubic feet in all.
How many yards of concrete for a 10x12 slab 4 inches thick?
The 10x12 measures out at 1.48 cubic yards, or 1.63 with 10% for waste. Order 1.75 cu yd for the 10x12, since ready-mix is sold in quarter yards with a 1 yard minimum at most plants.
How much does a 10x12 concrete slab 4 inches thick cost?
Concrete alone for the 10x12 runs about $305 – $425 for 1.75 cu yd of ready-mix delivered, short-load fee included, or $490 – $686 for 98 60 lb bags. Add a 4 in gravel base and wire mesh and the bagged 10x12 plan comes to $606 – $875. Labor, forms and finishing for a 10x12 at 4 in come on top of these national ranges (as of 2026-09), which are not quotes.
How much does a 10x12 concrete slab 4 inches thick weigh?
About 6,600 lb (3.3 tons) of wet concrete for the 10x12, at 150 lb per cubic foot. The 74 80 lb bags for a 10x12 weigh 5,920 lb: about 4 trips in a pickup carrying 1,500 lb a load.
Where do control joints go on a 10x12 slab 4 inches thick?
On a 10x12 at 4 in, every 8 to 12 ft (24 to 36 times the thickness), sawn 1 in deep. On the 10x12 at 4 in, a joint every 10 ft or less means 1 joint across the 12 ft side and 1 joint across the 10 ft side: 4 panels of about 6 × 5 ft and 22 ft of saw cut.
Limitations
The 10x12 figures at 4 in are material estimates and typical price ranges, not a quote or a structural design. Confirm that 4 in, the reinforcement and the joint layout suit your soil, loads and local code for a 10x12 slab with a qualified professional.