How Much Concrete for a 10x10 Slab?
Concrete needed
1.36 cubic yards
A 10 by 10 slab at four inches, with ten percent on top for waste.
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How that number is worked out
These are the figures this page was built with and every line the calculator produces from them. Change anything above and all of it moves.
- Length10 ft
- Width10 ft
- Thickness4 in
- Waste allowance10 %
Concrete needed1.36 cubic yards
| Volume | 33.3 cu ft |
|---|---|
| Cubic yards before waste | 1.23 |
| Cubic yards with 10% waste | 1.36order to this number |
| Order in quarter yards | 1.5 cu yd |
| 60 lb bags, if bagging it | 82 |
| 80 lb bags, if bagging it | 62 |
The material list this produces
| Ready mix concrete, cubic yards | 1.5 |
|---|---|
| Rebar or mesh, sq ft of slab | 100 |
| Form lumber, linear ft | 40 |
Thickness compared
Thickness is the one number on this page worth arguing about, so here is the same slab at each of the usual four.
| Thickness | Concrete needed |
|---|---|
| 4 in | 1.36 cubic yards |
| 5 in | 1.7 cubic yards |
| 6 in | 2.04 cubic yards |
| 8 in | 2.72 cubic yards |
What else matters here
A hundred square feet is the most searched slab size there is, because it covers the small patio, the hot tub pad and the 10 by 10 shed all at once. At four inches it is a shade over one cubic yard once waste is in, which means one short load and no second trip.
The number to order to is the quarter yard figure, not the raw one. Ready mix is batched and billed in quarter yard steps, so asking for 1.36 gets you 1.5 anyway. Ordering the rounded figure yourself is how you avoid finding out at the end of the pour that the driver rounded down.
If this pad is for a hot tub, four inches is not enough. A filled spa with people in it runs 4,000 to 6,000 pounds over that footprint, and the standard specification for one is six inches with rebar. Switch the thickness above and the whole page moves with it.
What this calculator assumes
- One cubic yard is 27 cubic feet. A 4 inch slab is one third of a foot thick, not 4.
- A 60 lb bag yields about 0.45 cubic feet and an 80 lb bag about 0.60. Bags are for small pours only; past about one cubic yard, ready mix is cheaper and far less work.
- Ready mix is usually sold in quarter yard steps with a short load fee below one yard.
Questions people ask
How many cubic yards is a 10x10 slab at 4 inches?
1.23 cubic yards of actual volume, and 1.36 once a ten percent waste allowance is added. You would order 1.5, because ready mix comes in quarter yard steps.
How many bags of concrete for a 10x10 slab?
About 82 sixty pound bags or 62 eighty pound bags. That is a full day of mixing for one person and is the main reason a slab this size is normally delivered.
How thick should a 10x10 patio slab be?
Four inches for foot traffic and furniture. Six for a hot tub, for anything you will drive on, or where the ground freezes deep and the base is not well drained.
The concrete calculator takes any dimensions you like and hands back the same list.