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How Much Concrete for a 12 × 16 Slab?

A 12 × 16 ft slab is 192 sq ft. It needs 2.61 cubic yards of concrete at 4 inches thick or 3.91 yd³ at 6 inches, including 10% extra.

12 × 16 ft slab, 10% extra included
Order4 in thick6 in thick
Cubic yards2.613.91
80-lb bags118176
60-lb bags157235
50-lb bags188282
40-lb bags235352
Cubic meters1.992.99
What are you pouring?
Units

Slab, patio or driveway

4 in is typical for patios and walks; 5–6 in for driveways and garage floors.

Bag size
Add your prices (optional)

Use your supplier's prices. We don't show average prices because they vary too much by area.

Concrete needed

2.61 cubic yards

70.4 ft³ · 1.99 m³ · includes 10% extra

You need about 2.61 cubic yards of concrete, or 118 bags of 80 lb mix.

Bags of premix

  • 23540 lb bags
  • 18850 lb bags
  • 15760 lb bags
  • 11880 lb bags
  • Before extra2.37 yd³ (64.0 ft³)
  • Weight of bags9,440 lb
  • Ready-mix costAdd a price per yd³
  • Bagged costAdd a price per bag

One 80 lb bag makes about 0.60 ft³ (manufacturer's published yield). Bags are rounded up.

At 2.61 yd³ that is 118 × 80 lb bags (9,440 lb) to mix. Most people order ready-mix at this size; ask suppliers for their minimum load and any short-load fee.

Estimate only, not a quote or engineering advice. Disclaimer

A 12 × 16 ft slab fits a mid-size shed or a patio with room for a dining table and a grill.

12 × 16 slab at other thicknesses

Concrete for a 12 × 16 ft slab
Thicknessyd³ exactyd³ +10%80-lb bags60-lb bags
3.5 in2.072.28103137
4 in2.372.61118157
5 in2.963.26147196
6 in3.563.91176235
8 in4.745.21235313

How it's worked out

12 × 16 = 192 sq ft · 192 × 4 ÷ 12 = 64.0 ft³ · ÷ 27 = 2.37 yd³ · × 1.10 = 2.61 yd³

For bags, the 70.4 ft³ (with extra) is divided by each bag's yield: 0.60 ft³ for 80 lb, 0.45 for 60 lb, 0.375 for 50 lb and 0.30 for 40 lb, then rounded up. At 4 inches the slab itself weighs about 9,000 lb, using the 140 lb/ft³ unit weight QUIKRETE lists for its Concrete Mix.

Bags or a truck?

At 2.61 yd³ you would need 118 × 80-lb bags (about 9,440 lb) and a long session with a mixer and helpers. Most people order ready-mix at this size: call suppliers with the yardage and ask for their minimum load and any short-load fee.

Don't forget the base: most slabs sit on a compacted layer of gravel, and thicker edges or footings around the perimeter add concrete. Use the footing calculator for a thickened edge.

Frequently asked questions

How many yards of concrete for a 12x16 slab?

2.37 cubic yards at 4 inches thick and 3.56 yd³ at 6 inches, before waste. With 10% extra, order 2.61 or 3.91 yd³.

How many bags of concrete for a 12x16 slab?

At 4 inches with 10% extra: 118 bags of 80-lb mix, 157 of 60 lb, 188 of 50 lb or 235 of 40 lb. At 6 inches: 176 bags of 80 lb or 235 of 60 lb.

How many cubic feet of concrete for a 12x16 slab?

64.0 ft³ at 4 inches (192 sq ft × 4 ÷ 12) and 96.0 ft³ at 6 inches, before waste.

How thick should a 12x16 slab be?

Four inches is usual for patios, walkways and shed pads. Garage floors, driveways and pads for heavy loads are commonly 5 to 6 inches. Follow local code or your plans for anything structural.

Other slab sizes

Related

Sources