How many bags for a 10x10 slab, by thickness
For a fixed 10x10 size, thickness is what changes the bag count. A 10x10 concrete slab at 6 inches needs about half again as many bags as the same slab at 4 inches. The chart below covers the four common pre-mixed bag sizes and includes 10% extra for spillage, uneven ground and form flex.
| Thickness | Concrete | 80 lb bags | 60 lb bags | 50 lb bags | 40 lb bags |
|---|---|---|---|---|---|
| 4 in | 1.36 yd³ | 62 | 82 | 98 | 123 |
| 5 in | 1.70 yd³ | 77 | 102 | 123 | 153 |
| 6 in | 2.04 yd³ | 92 | 123 | 147 | 184 |
10 × 10 ft slab, 10% extra included. Bag yields from the Quikrete Concrete Mix 1101 data sheet.
Without extra
These are the exact counts for a perfectly flat base with no waste. Use them only to check a quote; order from the chart above.
| Thickness | 80 lb | 60 lb | 50 lb | 40 lb |
|---|---|---|---|---|
| 4 in | 56 | 75 | 89 | 112 |
| 5 in | 70 | 93 | 112 | 139 |
| 6 in | 84 | 112 | 134 | 167 |
How we calculated it
The math for how many bags of concrete for a 10 x 10 slab takes four steps:
- Area: 10 ft × 10 ft = 100 sq ft
- Volume: 100 × (4 ÷ 12) = 33.3 cubic feet
- Add 10% extra: 33.3 × 1.10 = 36.7 cubic feet
- Divide by bag yield: 80 lb bag ≈ 0.60 cu ft → 36.7 ÷ 0.60 = 61.1 → round up to 62 bags
Always round up. A partial bag still has to be bought, and running short in the middle of a pour is worse than having one bag left over. Each bag size yields a different volume of mixed concrete:
| Bag size | Yield |
|---|---|
| 80 lb | 0.60 cu ft |
| 60 lb | 0.45 cu ft |
| 50 lb | 0.375 cu ft |
| 40 lb | 0.30 cu ft |
Source: Quikrete Concrete Mix No. 1101 data sheet.
Other common slab sizes
The same method works for any pad or patio. Here are a few nearby sizes at 4 inches thick, with 10% extra.
| Size | 80 lb bags | 60 lb bags |
|---|---|---|
| 8 × 10 ft | 49 | 66 |
| 10 × 12 ft | 74 | 98 |
| 12 × 12 ft | 88 | 118 |
| 10 × 20 ft | 123 | 163 |
4 in thick, 10% extra included.
For any other size, use the concrete slab cost calculator. Planning a 10 × 12 pad? See the 10x12 concrete slab cost guide for prices by thickness.
Bags or ready-mix?
A 10 × 10 slab at 4 inches needs about 1.36 cubic yards. That is roughly 62 bags to mix by hand, which is a lot of work for one pour. Ready-mix delivered by truck typically costs about $119–$147 per cubic yard (HomeGuide).
But orders under 10 cubic yards often add a short-load fee of about $53 per yard (HomeGuide). Compare both before you buy.
Tips before you pour
- Measure the thickness after the gravel base is compacted, not before.
- Order a little extra: running short mid-pour leaves a weak joint.
- Bags are heavy: 62 bags of 80 lb mix weigh about 4,960 lb in total. Check your vehicle’s payload or ask for delivery.
Frequently asked questions
How many 80 lb bags of concrete do I need for a 10x10 slab?
About 62 bags for a 4-inch slab with 10% extra, or 56 bags with no extra.
How many 60 lb bags for a 10x10 slab?
About 82 bags at 4 inches thick with 10% extra.
How many bags for a 10x10 slab 6 inches thick?
About 92 bags of 80 lb concrete, or 123 bags of 60 lb, with 10% extra.
How many cubic yards is a 10x10 slab?
About 1.23 cubic yards at 4 inches thick, or 1.36 with 10% extra.
Sources
- Quikrete — Concrete Mix No. 1101 Data Sheet (bag yields)
- HomeGuide — How Much Does Concrete Cost Per Yard? (Jan 6, 2026)
Related
- Concrete slab cost calculatorAny size: cubic yards, 60 & 80 lb bags, and installed or DIY cost.
- Gravel calculatorHow much gravel you need for the base layer, in yards and tons.
- How many tons in a yard of gravelWeight per cubic yard for common gravel types.
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