Concrete planning guide
How Much Concrete for a 10x10 Slab?
Compare concrete volume and bag counts for a 10 ft by 10 ft slab at common planning thicknesses.
Before you use this guide
This guide is a calculator companion. It explains typical planning inputs, unit conversions, and material estimate assumptions so you can use the related calculator with better context. It does not provide live prices, contractor quotes, building-code guidance, structural design, or product-specific installation instructions.
A 10x10 concrete slab has an area of 100 square feet. The material quantity depends mainly on slab thickness. A 4 inch slab needs much less concrete than a 6 inch or 8 inch slab, and bag counts change quickly because concrete bags have fixed yields.
This guide shows the arithmetic for a rectangular 10 ft by 10 ft slab. It is for material quantity planning only. It does not design the slab, choose reinforcement, check subgrade, handle permits, or decide whether bagged concrete or ready-mix is appropriate for your project.
10x10 slab concrete quantity by thickness
Bag counts are rounded up. The bag estimates use common approximate yields: 40 lb = 0.30 cu ft, 60 lb = 0.45 cu ft, 80 lb = 0.60 cu ft.
| Thickness | Cubic feet | Cubic yards | 40 lb bags | 60 lb bags | 80 lb bags |
|---|---|---|---|---|---|
| 4 in | 33.33 cu ft | 1.23 cu yd | 112 bags | 75 bags | 56 bags |
| 6 in | 50.00 cu ft | 1.85 cu yd | 167 bags | 112 bags | 84 bags |
| 8 in | 66.67 cu ft | 2.47 cu yd | 223 bags | 149 bags | 112 bags |
These table values do not include waste. Add a waste factor when your forms, excavation, or subgrade are uneven.
Example: 10x10 slab at 4 inches thick
Inputs
- Length: 10 ft
- Width: 10 ft
- Thickness: 4 in
- Bag yield: 0.60 cu ft per 80 lb bag
Estimated result
The slab volume is about 33.33 cubic feet, or 1.23 cubic yards. At 0.60 cu ft per 80 lb bag, the estimate rounds up to 56 bags before waste.
Convert 4 inches to 0.333 feet, then multiply 10 x 10 x 0.333. Divide by 27 for cubic yards and by bag yield for bag count.
Example: 10x10 slab at 6 inches thick
Inputs
- Length: 10 ft
- Width: 10 ft
- Thickness: 6 in
- Bag yield: 0.60 cu ft per 80 lb bag
Estimated result
The slab volume is about 50.00 cubic feet, or 1.85 cubic yards. At 0.60 cu ft per 80 lb bag, the estimate rounds up to 84 bags before waste.
A 6 inch slab is 50% thicker than a 4 inch slab, so the concrete volume and bag count also increase by about 50%.
Bag count is not a shopping quote
Bag yield varies by product and mix. Check the yield printed on the bag you plan to use, then add waste if your form depth is not perfectly uniform.
Run your own slab dimensions
FAQ
How many cubic yards are in a 10x10 slab at 4 inches thick?
A 10 ft by 10 ft slab at 4 inches thick is about 33.33 cubic feet, which is about 1.23 cubic yards before waste.
How many 80 lb bags do I need for a 10x10 slab?
At 4 inches thick, the estimate is about 56 bags before waste if each 80 lb bag yields about 0.60 cubic feet. Thicker slabs need more bags.
Should I add waste to a concrete slab estimate?
Usually yes. Forms, excavation, subgrade unevenness, spillage, and depth variation can increase the amount needed. Many planning estimates use a small waste factor.
Does this guide tell me whether to use ready-mix concrete?
No. This guide estimates quantity only. Delivery method, minimum orders, job timing, access, and local suppliers are outside the scope of this site.