Concrete needed for a 12 × 16 ft slab, by thickness
These figures are for the whole 192 ft² slab. The last column adds 10% for waste, which is what we suggest you order.
| Thickness | Cubic feet | Cubic yards | 80 lb bags | 60 lb bags | Yards with 10% waste |
|---|---|---|---|---|---|
| 4 in | 64.0 | 2.37 | 107 | 143 | 2.61 |
| 5 in | 80.0 | 2.96 | 134 | 178 | 3.26 |
| 6 in | 96.0 | 3.56 | 160 | 214 | 3.91 |
| 8 in | 128.0 | 4.74 | 214 | 285 | 5.21 |
What a 12 × 16 slab is used for
A 12 × 16 ft slab is a large patio, a floor for a 12 × 16 outbuilding or cabin, or a short single-lane driveway apron. Four inches for a patio. For a driveway apron or a building with a vehicle or heavy equipment, go to 5 or 6 inches.
Bags or ready-mix for 12 × 16 ft?
At 2.61 cubic yards, ready-mix is the sensible choice. Doing it with bags would mean 118 bags (about 4.7 tons of dry mix), which is too much to mix by hand before the first batch starts to set. Ask your supplier about their minimum order and how long you have to unload.
Don't forget what goes under and inside it
A slab needs a compacted base, usually 4 inches of gravel, which for this size is about 2.84 cubic yards after allowing for compaction (see the gravel calculator). Reinforcement such as rebar or wire mesh holds cracks tight: the rebar calculator counts bars for a 12 × 16 ft grid.
Want to change anything else? The calculator above is the full Concrete Calculator: edit any number and the results update instantly.
Tools & materials for this project
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Frequently asked questions
How many bags of concrete for a 12x16 slab?
For a 4 inch slab you need 107 bags of 80 lb concrete (143 bags of 60 lb), or 118 bags of 80 lb with 10% waste. For a 6 inch slab it is 160 bags of 80 lb, or 176 with 10% waste.
How many cubic yards is a 12x16 slab?
A 12 × 16 ft slab is 2.37 yd³ at 4 inches, 2.96 yd³ at 5 inches and 3.56 yd³ at 6 inches, before waste. Add 5 to 10% when you order.
How much does a 12x16 concrete slab weigh?
At 4 inches thick it weighs roughly 9,600 lb (4.8 tons), at about 150 lb per cubic foot. At 6 inches it is about 14,400 lb.
Related sizes and guides
Estimates only. Results assume standard materials and simple shapes. Supplier products vary, and the final call on quantity, structure and safety is yours. Check your local code and your supplier's guidance before ordering.