12x16 Concrete Slab, 4 Inches Thick
A 12 × 16 ft slab (192 sq ft) at 4 in thick takes about 2.61 cubic yards of concrete, with 10% extra for waste. For ready-mix, order 2.75 cu yd for the 12x16, about $445 – $605 delivered, short-load fee included. Bagged, the same 12x16 is 118 80 lb or 157 60 lb bags, about $785 – $1,099 for the concrete alone.
- Ready-mix order
- 2.75 cu yd
- Ready-mix cost
- $445 – $605
- 80 lb bags
- 118
- Bag cost
- $785 – $1,099
Materials only for a 12x16 at 4 in, from national price ranges as of 2026-09; not a live quote.
What a 12x16 slab is for
A 12x16 pad suits a large garden shed or backyard workshop, a patio that holds a dining table at one end and two lounge chairs at the other, or the floor of a screened porch.
At 192 sq ft, a shed this size is over the most common 120 sq ft permit exemption, so expect a permit and maybe an inspection of the forms before you pour.
Workshop sheds this size often get a power circuit, so it pays to run an empty conduit under the slab now rather than trench later.
A 4 in 12x16 pour: check first
- Ask for the permit early; some towns want a site plan showing the distance to the lot lines.
- Lay an empty conduit sleeve under the pad if power might ever go to the shed.
- Mark the door location so you can keep the threshold edge clean and level.
Full plan for a 12x16 slab, 4 in
- Area
- 192 sq ft
- Thickness
- 4 in
- Volume
- 2.61 cu yd
Bagged concrete estimate (DIY)
$971 – $1,402
Est. as of 2026-09 — not a live quote
Ready-mix delivered, incl. short-load fee (materials only)
$445 – $605
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 235 × 40 lb, 188 × 50 lb or 118 × 80 lb bags. 157 bags
- Ready-mix concrete Alternative to bagged mix; most suppliers have a 1 cu yd order minimum. 2.75 cu yd
- Compactable gravel sub-base 4 in compacted base beneath the slab. 3.2 tons
- 6x6 welded wire mesh Reinforcement for crack control; not a substitute for engineered rebar on structural slabs. 212 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: 10,560 lb (5.3 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 12x16 slab, 4 in?
At 2.61 cu yd, the 12x16 sits where bagged concrete and ready-mix cross over in price. For the 12x16, 118 80 lb bags cost about $785 – $1,099, while 2.75 cu yd of ready-mix costs about $445 – $605, short-load fee included. Ready-mix wins for this 12x16 by roughly $417 (range midpoints), and nobody has to mix 118 bags by hand.
Is 4 in thick enough for a 12x16 slab?
4 in is the usual thickness for a 12x16 patio, walkway, shed floor or equipment pad that carries foot traffic.
Control joints for a 12x16 slab at 4 in
A 12x16 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 12x16 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 12x16 at 4 in, a joint every 10 ft or less means 1 joint across the 16 ft side and 1 joint across the 12 ft side: 4 panels of about 8 × 6 ft and 28 ft of saw cut.
How much a 12x16 slab 4 in thick weighs
Wet concrete weighs about 150 lb per cubic foot, so the 12x16 pour is about 10,560 lb (5.3 tons). As bags, the 12x16 is 118 80 lb bags, 9,440 lb in all: about 7 trips in a pickup carrying 1,500 lb a load. Nobody hauls 9,440 lb of bags for a 12x16 in a pickup; it comes by ready-mix truck or as pallets on a delivery truck.
The 12x16 at 4 in against nearby sizes
Every row uses the same 10% waste and prices as the 12x16 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 |
|---|---|---|---|---|---|---|
| 12x12 slab, 4 in | 1.96 | 118 | 88 | 2 cu yd | $590 – $826 | $340 – $470 |
| 12x16 slab, 4 in (this page) | 2.61 | 157 | 118 | 2.75 cu yd | $785 – $1,099 | $445 – $605 |
| 14x14 slab, 4 in | 2.66 | 160 | 120 | 2.75 cu yd | $800 – $1,120 | $445 – $605 |
Questions about a 12x16 slab, 4 in
How many bags of concrete for a 12x16 slab 4 inches thick?
A 12x16 slab at 4 in takes about 118 80 lb bags or 157 60 lb bags (or 188 50 lb, 235 40 lb), with 10% added for waste: 70.4 cubic feet in all.
How many yards of concrete for a 12x16 slab 4 inches thick?
2.61 cubic yards with waste (2.37 without) for a 12x16 at 4 in. Round the 12x16 order to 2.75 cu yd: plants batch in quarter yards and most won't send less than a yard.
How much does a 12x16 concrete slab 4 inches thick cost?
Concrete alone for the 12x16 runs about $445 – $605 for 2.75 cu yd of ready-mix delivered, short-load fee included, or $785 – $1,099 for 157 60 lb bags. Add a 4 in gravel base and wire mesh and the bagged 12x16 plan comes to $971 – $1,402. Labor, forms and finishing for a 12x16 at 4 in come on top of these national ranges (as of 2026-09), which are not quotes.
How much does a 12x16 concrete slab 4 inches thick weigh?
About 10,560 lb (5.3 tons) of wet concrete for the 12x16, at 150 lb per cubic foot. The 118 80 lb bags for a 12x16 weigh 9,440 lb: about 7 trips in a pickup carrying 1,500 lb a load.
Where do control joints go on a 12x16 slab 4 inches thick?
On a 12x16 at 4 in, every 8 to 12 ft (24 to 36 times the thickness), sawn 1 in deep. On the 12x16 at 4 in, a joint every 10 ft or less means 1 joint across the 16 ft side and 1 joint across the 12 ft side: 4 panels of about 8 × 6 ft and 28 ft of saw cut.
Limitations
The 12x16 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 12x16 slab with a qualified professional.