16x16 Concrete Slab, 4 Inches Thick
A 16 × 16 ft slab (256 sq ft) at 4 in thick takes about 3.48 cubic yards of concrete, with 10% extra for waste. For ready-mix, order 3.5 cu yd for the 16x16, about $550 – $740 delivered, short-load fee included. Bagged, the same 16x16 is 157 80 lb or 209 60 lb bags, about $1,045 – $1,463 for the concrete alone.
- Ready-mix order
- 3.5 cu yd
- Ready-mix cost
- $550 – $740
- 80 lb bags
- 157
- Bag cost
- $1,045 – $1,463
The 16x16 (4 in) prices are national material ranges as of 2026-09, not a quote from a supplier.
Where a 16x16 slab makes sense
Two hundred fifty-six square feet is a full outdoor room: a dining table, a seating group and a grill can share a 16x16 patio without anyone squeezing past a chair.
This size is also the footprint of many backyard pavilions and larger gazebos, and of a single-car-width studio or workshop that does not need to hold a car.
A square this big is easier to finish in two halves, with a control joint down the middle, than as one large surface, especially for a first-time finisher.
Before you pour the 16x16 at 4 in
- Plan the finishing in sections and have a second person on the screed board.
- A pavilion with posts on the slab may need a thicker footing under each post: check the kit or the plans.
- Order a broom finish for a patio this size: it is easier for a beginner than a trowel-smooth surface and less slippery.
Full plan for a 16x16 slab, 4 in
- Area
- 256 sq ft
- Thickness
- 4 in
- Volume
- 3.48 cu yd
Bagged concrete estimate (DIY)
$1,293 – $1,867
Est. as of 2026-09 — not a live quote
Ready-mix delivered, incl. short-load fee (materials only)
$550 – $740
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 313 × 40 lb, 251 × 50 lb or 157 × 80 lb bags. 209 bags
- Ready-mix concrete Alternative to bagged mix; most suppliers have a 1 cu yd order minimum. 3.5 cu yd
- Compactable gravel sub-base 4 in compacted base beneath the slab. 4.27 tons
- 6x6 welded wire mesh Reinforcement for crack control; not a substitute for engineered rebar on structural slabs. 282 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: 14,080 lb (7 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 16x16 slab, 4 in?
3.48 cu yd for the 16x16 fits on one ready-mix truck (they carry about 8 to 10 cu yd). In bags the 16x16 would be 157 80 lb bags weighing 12,560 lb, so ready-mix is the practical choice. Under 10 cu yd most suppliers add a short-load fee, and the $550 – $740 range for the 16x16 includes one. On the 16x16, ready-mix comes out cheaper by about $609 at the middle of each range, and it saves mixing 157 bags.
Is 4 in thick enough for a 16x16 slab?
4 in is the usual thickness for a 16x16 patio, walkway, shed floor or equipment pad that carries foot traffic.
Control joints for a 16x16 slab at 4 in
Like any slab, a 4 in 16x16 shrinks while it cures; control joints decide where its cracks go. The usual rule (ACI and PCA guidance) puts joints in a 16x16 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 16x16 at 4 in, a joint every 10 ft or less means 1 joint each way: 4 panels of about 8 × 8 ft and 32 ft of saw cut.
How much a 16x16 slab 4 in thick weighs
Wet concrete weighs about 150 lb per cubic foot, so the 16x16 pour is about 14,080 lb (7 tons). As bags, the 16x16 is 157 80 lb bags, 12,560 lb in all: about 9 trips in a pickup carrying 1,500 lb a load. Nobody hauls 12,560 lb of bags for a 16x16 in a pickup; it comes by ready-mix truck or as pallets on a delivery truck.
The 16x16 at 4 in against nearby sizes
Every row uses the same 10% waste and prices as the 16x16 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 |
|---|---|---|---|---|---|---|
| 12x20 slab, 4 in | 3.26 | 196 | 147 | 3.5 cu yd | $980 – $1,372 | $550 – $740 |
| 16x16 slab, 4 in (this page) | 3.48 | 209 | 157 | 3.5 cu yd | $1,045 – $1,463 | $550 – $740 |
| 12x24 slab, 4 in | 3.91 | 235 | 176 | 4 cu yd | $1,175 – $1,645 | $620 – $830 |
Questions about a 16x16 slab, 4 in
How many bags of concrete for a 16x16 slab 4 inches thick?
Plan on 93.9 cubic feet for the 16x16, which is 157 80 lb bags, 209 60 lb bags, 251 50 lb or 313 40 lb bags once 10% waste is in.
How many yards of concrete for a 16x16 slab 4 inches thick?
The 16x16 measures out at 3.16 cubic yards, or 3.48 with 10% for waste. Order 3.5 cu yd for the 16x16, since ready-mix is sold in quarter yards with a 1 yard minimum at most plants.
How much does a 16x16 concrete slab 4 inches thick cost?
Concrete alone for the 16x16 runs about $550 – $740 for 3.5 cu yd of ready-mix delivered, short-load fee included, or $1,045 – $1,463 for 209 60 lb bags. Add a 4 in gravel base and wire mesh and the bagged 16x16 plan comes to $1,293 – $1,867. Labor, forms and finishing for a 16x16 at 4 in come on top of these national ranges (as of 2026-09), which are not quotes.
How much does a 16x16 concrete slab 4 inches thick weigh?
About 14,080 lb (7 tons) of wet concrete for the 16x16, at 150 lb per cubic foot. The 157 80 lb bags for a 16x16 weigh 12,560 lb: about 9 trips in a pickup carrying 1,500 lb a load.
Where do control joints go on a 16x16 slab 4 inches thick?
On a 16x16 at 4 in, every 8 to 12 ft (24 to 36 times the thickness), sawn 1 in deep. On the 16x16 at 4 in, a joint every 10 ft or less means 1 joint each way: 4 panels of about 8 × 8 ft and 32 ft of saw cut.
Limitations
The 16x16 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 16x16 slab with a qualified professional.