ContractorHandbook

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.

It does not stop at a number.

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length, ftthickness, inwidth, ftlength x width x (inches / 12) / 27 = cubic yards
Concrete is priced by the cubic yard and poured by the inch. The calculator turns the thickness into feet, multiplies out the volume, divides by 27, then rounds up to the quarter yard the truck actually sells.

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

Volume33.3 cu ft
Cubic yards before waste1.23
Cubic yards with 10% waste1.36order to this number
Order in quarter yards1.5 cu yd
60 lb bags, if bagging it82
80 lb bags, if bagging it62

The material list this produces

Ready mix concrete, cubic yards1.5
Rebar or mesh, sq ft of slab100
Form lumber, linear ft40

Thickness compared

The same slab at four thicknesses.

ThicknessConcrete needed
4 in1.36 cubic yards
5 in1.7 cubic yards
6 in2.04 cubic yards
8 in2.72 cubic yards

What else matters here

At four inches it is 1.36 cubic yards once waste is in.

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.

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 well past the point where a ready mix truck is easier and usually cheaper.

How thick should a 10x10 patio slab be?

Four inches for foot traffic and furniture. Five or six where vehicles will sit on it.

Different numbers?

The concrete calculator takes any dimensions you like and hands back the same list.

Other common sizes

19 more sizes are answered on the concrete calculator page