How Much Concrete for a 10x10 Slab?
A 10x10 concrete slab at the standard 4 inch thickness needs about 1.36 cubic yards of concrete, which works out to roughly 62 bags of 80 lb premixed concrete. Go thicker for a driveway and that number climbs fast. Below is the exact math, a bag count table for 4, 5 and 6 inches, and what to check on rebar, gravel and cost before you order.
Key takeaways
- A 10x10 slab at 4 inches deep needs 1.36 cubic yards of concrete (with 10% waste), or about 62 bags of 80 lb mix.
- At 5 inches it is about 1.70 cubic yards (77 bags); at 6 inches about 2.04 cubic yards (92 bags).
- Bagged concrete for a 4 inch, 10x10 slab runs roughly 380 to 400 dollars at current 80 lb bag prices.
- Ready-mix by the truck usually is not worth it below about 2 cubic yards; most suppliers charge a short-load fee for anything under their 3 to 5 yard minimum.
- Rebar is optional at 4 inches for a light-use patio, but recommended for driveways, heavy loads or slabs over 5 inches thick.
How much concrete for a 10x10 slab at 4 inches
A 10 by 10 foot slab covers 100 square feet. At the standard 4 inch residential thickness, that is 100 times 0.333 feet, or 33.3 cubic feet of concrete. Divide by 27 to convert to cubic yards and you get 1.23 cubic yards before waste.
Add a 10% waste allowance, since the subgrade is never perfectly flat and you cannot top off a pour once it starts, and the real order comes to about 1.36 cubic yards. In bags, that is roughly 62 bags of 80 lb premixed concrete.
If your project is not exactly 10x10 or you want to test a different thickness, the concrete slab calculator does the conversion and bag math for you instantly.
Concrete needed by thickness: patio vs driveway depth
Thickness changes the order more than most people expect. A 4 inch slab suits patios, walkways and sheds. A driveway or a slab that will carry a vehicle should go to 5 or 6 inches, which raises the concrete volume by a third to a half.
| Thickness | Cubic yards (+10%) | Cubic meters | 80 lb bags |
|---|---|---|---|
| 4 in (patio, walkway) | 1.36 | 1.04 | 62 |
| 5 in (heavier patio, shed) | 1.70 | 1.30 | 77 |
| 6 in (driveway, RV pad) | 2.04 | 1.56 | 92 |
If you are pricing a driveway rather than a patio, the full cost breakdown in how much a concrete driveway costs covers the thicker slab, base prep and finish options in more detail.
Bags vs ready-mix for a 10x10 pour
At 1.23 to 2 cubic yards, a 10x10 slab sits right at the line between bagged concrete and a delivered truck. Most ready-mix suppliers have a 3 to 5 cubic yard minimum order, and charge a short-load fee of about 40 to 100 dollars per yard below that minimum.
Nationally, ready-mix runs about 125 to 195 dollars per cubic yard in 2026, averaging near 150 to 165 dollars before delivery and short-load fees. For a 1.36 yard pour, that often lands close to 300 to 500 dollars once fees are added, similar to or higher than bags.
How many bags of concrete do I need for a 10x10 slab
Bag yield changes with bag size. An 80 lb bag yields about 0.60 cubic feet, a 60 lb bag about 0.45 cubic feet, and a 40 lb bag about 0.30 cubic feet, so smaller bags mean more of them for the same volume.
| Bag size | 4 in slab | 5 in slab | 6 in slab |
|---|---|---|---|
| 80 lb | 62 bags | 77 bags | 92 bags |
| 60 lb | 82 bags | 102 bags | 122 bags |
| 40 lb | 122 bags | 153 bags | 183 bags |
Cubic feet = 10 x 10 x (Thickness(in) ÷ 12)Bags = (Cubic feet x 1.10) ÷ bag yield(ft3)
Do you need rebar or gravel under a 10x10 slab
A basic 4 inch patio or walkway slab on stable, well-compacted soil can get by with welded wire mesh, or no reinforcement at all for light foot traffic. Rebar becomes the standard choice once the slab is over 5 inches thick, carries a vehicle, sits near a structure, or crosses soft or disturbed ground.
If you do reinforce a 10x10 slab, a grid spaced 18 inches on center takes about 140 feet of rebar, closer to 154 feet once you add 10 to 15% for overlaps and cut waste. The full breakdown of bar sizes and spacing is in how much rebar do I need.
Underneath, plan on 4 to 6 inches of compacted gravel base for a patio-grade slab, moving up to 6 to 8 inches for a driveway or for clay and expansive soils. Skipping the gravel base is one of the most common reasons a slab cracks or heaves within a few years.
Ordering the right amount without running short
The most common ordering mistake is forgetting the 10% waste factor, or measuring thickness as an average instead of the deepest point of an uneven subgrade. Both leave you short mid-pour, which is the worst time to find out.
Keep length and width in feet, convert thickness from inches to feet before multiplying, and round bag orders up rather than down. If the slab is not a clean 10x10, or you are comparing a patio against a full driveway pour, the cost side is covered separately in how much a concrete patio costs.
For the exact yardage, bag count and an optional cost estimate on your own dimensions, run the numbers through the concrete slab calculator before you head to the supplier.
Frequently asked questions
How many 80lb bags of concrete do I need for a 10x10 slab?
Do you need rebar for a 10x10 concrete slab?
Do I need gravel under a concrete slab?
How thick should a 10x10 concrete slab be?
Is it cheaper to use bags or order ready-mix for a 10x10 slab?
References
- Concrete (Wikipedia)
- QUIKRETE Concrete Mix yield (spec sheet)
- ACI 302: Concrete Floor and Slab Construction
- NRMCA: Ready Mixed Concrete