How Many Bags of Concrete for an 8x10 Slab?
An 8 by 10 foot slab at 4 inches holds 26.67 cubic feet of concrete. How many bags of concrete for an 8x10 slab comes to 45 bags of 80 lb mix or 60 of the 60 lb size, before a spare bag or two for waste.
Concrete calculator →How the bag count is figured
- Area: 8 × 10 = 80 sq ft.
- Volume at 4 in: 80 × 0.333 = 26.67 cu ft.
- 80 lb bags: 26.67 ÷ 0.60 = 44.4, round up to 45.
- 60 lb bags: 26.67 ÷ 0.45 = 59.3, round up to 60.
Check the yield printed on your brand’s bag, since it varies a little. The concrete calculator handles other shapes.
Related: How Much Concrete for an 8x10 Slab?
Bags by thickness for an 8x10 slab
| Thickness | Cubic feet | 80 lb bags | 60 lb bags | 40 lb bags |
|---|---|---|---|---|
| 3 in | 20.00 | 34 | 45 | 67 |
| 4 in | 26.67 | 45 | 60 | 89 |
| 5 in | 33.33 | 56 | 75 | 112 |
| 6 in | 40.00 | 67 | 89 | 134 |
When bags make sense
Bags win on small pads because there is no delivery or short-load charge. The tradeoff is labor: 45 bags of 80 lb mix is 3,600 pounds to lift, pour and mix. A small drum mixer keeps batches consistent, and a helper keeps the pour moving so the edges do not set before the middle.
Related: How Many Bags of Concrete for a 10x10 Slab?
Prep for a small slab
A small slab still needs a firm base. Compact the soil, add compacted gravel and set forms to the finished height. If the pad will hold an AC unit, a generator or a grill, keep the top a little above the surrounding grade so water does not pool against it. Mix to a stiff, oatmeal-like consistency; extra water makes it easier to place but weaker.
Buying the bags
A pallet of 80 lb bags often holds around 40 to 42 bags, so this job is about 2 pallets or less. Buy one or two extra bags: returning an unopened bag is easier than running out mid-pour.
Questions people ask
How many 80 lb bags for an 8x10 slab?
About 45 bags at 4 inches thick.
How many 60 lb bags for an 8x10 slab?
About 60 bags at 4 inches thick.
How many bags for an 8x10 slab 6 inches thick?
About 67 bags of 80 lb mix or 89 of 60 lb.
How much does an 80 lb bag of concrete yield?
About 0.6 cubic feet of mixed concrete.
How thick should the base under the slab be?
About 4 inches of compacted gravel is common for residential slabs, more on soft or poorly drained soil.
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
- How Many Bags of Concrete for a 7x7 Slab?
- How Many Bags of Concrete for an 8x8 Slab?
As an Amazon Associate, AsphaltTons.com earns from qualifying purchases. Product links below are sponsored.