How Much Concrete for a 10x28 Slab?
How much concrete for a 10x28 slab depends on thickness. The slab covers 10 × 28 = 280 square feet, and at 4 inches thick that is about 3.46 cubic yards, or 3.80 yards with a 10 percent allowance. Mixed from bags, it is roughly 156 bags of 80 lb mix.
Concrete calculator →The math for a 10x28 slab
- Area: 10 ft × 28 ft = 280 sq ft.
- Thickness in feet: 4 in ÷ 12 = 0.333 ft.
- Volume: 280 × 0.333 = 93.3 cubic feet.
- Cubic yards: 93.3 ÷ 27 = 3.46 yd³.
- With 10% extra: 3.80 yd³.
The concrete calculator runs the same steps for any size and thickness.
Related: How Much Concrete for a 12x20 Slab?
Concrete for a 10x28 slab by thickness
| Thickness | Cubic feet | Cubic yards | Yards +10% | 80 lb bags | 60 lb bags |
|---|---|---|---|---|---|
| 4 in | 93.3 | 3.46 | 3.80 | 156 | 208 |
| 5 in | 116.7 | 4.32 | 4.75 | 195 | 260 |
| 6 in | 140.0 | 5.19 | 5.70 | 234 | 312 |
Bag counts assume about 0.60 cubic feet per 80 lb bag and 0.45 per 60 lb bag, rounded up.
Choosing the thickness
Four inches is the usual thickness for patios, walks and shed floors. Slabs that carry cars or a heavy hot tub are often poured at 5 to 6 inches, and edges are sometimes thickened where loads concentrate.
Related: How Much Concrete for a 12x24 Slab?
Placing the order
Ready-mix is priced and batched by the cubic yard (27 cubic feet). Plants commonly add a small-load fee when an order is under a set minimum, so ask about it when you call. Ordering a little extra costs far less than a second truck.
Prep before the pour
Prep matters as much as the yardage. Strip sod and soft soil, compact the subgrade, then add a compacted stone base, commonly about 4 inches. A level, firm base also keeps your thickness even, which keeps the yardage close to the math.
Keeping cracks under control
Cut or tool control joints so the slab cracks where you want it to. A common rule is spacing them, in feet, at no more than two to three times the slab thickness in inches, so about 10 feet apart for a 4-inch slab, and about a quarter of the slab depth deep.
Questions people ask
How many yards of concrete for a 10x28 slab at 4 inches?
About 3.46 cubic yards, or 3.80 with 10 percent extra.
How many yards for a 10x28 slab at 6 inches?
About 5.19 cubic yards.
How many 80 lb bags for a 10x28 slab?
About 156 bags at 4 inches thick, before any waste allowance.
How many square feet is a 10x28 slab?
280 square feet.
How much does a cubic yard of concrete weigh?
Roughly 4,000 pounds, or about 2 tons, for normal-weight concrete.
When is bagged concrete practical?
Usually for jobs under about a cubic yard. Beyond that, mixing dozens of bags by hand gets slow and batches may not blend well.
Related guides
- How Much Area Does a Yard of Concrete Cover?
- How Many Bags of Concrete in a Yard? 40, 60, 80 lb
- Gravel Base Under a Concrete Slab: Depth and Tons
- How Many Yards in a Concrete Truck? Mixer Sizes
- Concrete Short Load Fee: What It Is and How to Cut It
- 60 lb vs 80 lb Concrete Bags: Yield, Count, and Cost
- Rebar vs Wire Mesh in a Slab: Which One to Use
- Cost to Pour a Concrete Slab: Per Square Foot
- How Much Concrete for a 10x25 Slab?
- How Much Concrete for a 10x26 Slab?
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