The amount of concrete needed per square foot depends on the thickness of the concrete slab. Typically, for a standard 10 cm (4 inches) thick slab, you would need around 0.333 cubic feet or 0.012 cubic yards of concrete per square foot.

Ready mix concrete is mixture of Portland cement, sand and aggregate with some admixture like accelerator, reducer, plasticizer. Each ingredients of concrete required in adequate quantities according to achieve targeted compressive strength or design of a concrete structure.

Ready mix concrete can be used for building or repairing foundation walls, fence post, sidewalks, curbs, steps, shed floor, pergolas, concrete path and ramps and for setting posts and others concrete structure like, footing, slab, beam and columns.

Weight of Ready mix concrete in dry condition is about 133 lbs per cubic foot, 3600 lbs per cubic yard, 17.826lb/ gallon, 21.36kN/ m3, 2.136kg/ litre, 1.234 oz/ inch3, 60kg/ CF, or which is approximately equal as 2136 kg per cubic meter. The weight of concrete is determined by its density, which can vary based on the amount of aggregate, water, and air in the mix.

You need to calculate the volume of concrete in cubic feet before ordering the mixed concrete. Concrete is usually ordered in cubic feet, cubic yards, or cubic meters. The volume of required concrete quantity is calculated by multiplying length, width and depth of slab. Generally depth will be 4 inches, 5 inches, 6 inches and 8 inches.

The Concrete Calculator estimates the volume and weight of concrete necessary to cover a given area. Purchasing slightly more concrete than the estimated result can reduce the probability of having insufficient concrete

## How much concrete do i need per square foot

Typically for a standard 4 inches thick slab, you would need about 0.333 cubic feet of concrete per square foot, while for a 6 inch thick slab, you would need about 0.5 cubic feet of concrete per square foot. Likewise, while for a 5 inch thick slab, you would need about 0.417 cubic feet of concrete per square foot, while for a 8 inch thick slab, you would need about 0.667 cubic feet of concrete per square foot. In addition, for a 3 inch thick slab, you would need about 0.25 cubic feet of concrete per square foot.

### How much concrete do i need per square foot at 4 inches thick

How do i figure out how much concrete do i need per square foot depending on thickness of your slab and area of slab which on concrete is poured. Lets do calculation:-

At 4 inches thick:-

1) Determine how thick you want the concrete, suppose thickness = 4″, area = 1 ft2

2) Convert the thickness from inches to feet

Such as 4/12 = 0.333 feet

3) Multiply the thickness in feet by the square foot area to determine cubic feet of concrete you need such as 1×0.333 = 0.333 cubic feet.

4) convert cubic feet of concrete in cubic yards by dividing by 27 such as 0.333/27 = 0.012 cubic yards

Thus, you need 0.333 cubic feet or 0.012 cubic yards of concrete per square foot at 4 inches thick.

### How much concrete do i need per square foot at 5 inches thick

At 5 inches thick:-

1) Determine how thick you want the concrete, suppose thickness = 5″, area = 1 ft2

2) Convert the thickness from inches to feet

Such as 5/12 = 0.417 feet

3) Multiply the thickness in feet by the square foot area to determine cubic feet of concrete you need such as 1×0.417 = 0.417 cubic feet.

4) convert cubic feet of concrete in cubic yards by dividing by 27 such as 0.417/27 = 0.015 cubic yards

Thus, you need 0.417 cubic feet or 0.015 cubic yards of concrete per square foot at 5 inches thick.

### How much concrete do i need per square foot at 6 inches thick

At 6 inches thick:-

1) Determine how thick you want the concrete, suppose thickness = 6″, area = 1 ft2

2) Convert the thickness from inches to feet

Such as 6/12 = 0.5 feet

3) Multiply the thickness in feet by the square foot area to determine cubic feet of concrete you need such as 1×0.5 = 0.5 cubic feet.

4) convert cubic feet of concrete in cubic yards by dividing by 27 such as 0.5/27 = 0.0185 cubic yards

Thus, you need 0.5 cubic feet or 0.0185 cubic yards of concrete per square foot at 6 inches thick.

### How much concrete do i need per square foot at 8 inches thick

At 8 inches thick:-

1) Determine how thick you want the concrete, suppose thickness = 8″, area = 1 ft2

2) Convert the thickness from inches to feet

Such as 8/12 = 0.667 feet

3) Multiply the thickness in feet by the square foot area to determine cubic feet of concrete you need such as 1×0.667 = 0.667 cubic feet.

4) convert cubic feet of concrete in cubic yards by dividing by 27 such as 0.667/27 = 0.0185 cubic yards

Thus, you need 0.667 cubic feet or 0.0185 cubic yards of concrete per square foot at 8 inches thick.

### How much concrete do i need per square foot at 3 inches thick

At 3 inches thick:-

1) Determine how thick you want the concrete, suppose thickness = 3″, area = 1 ft2

2) Convert the thickness from inches to feet

Such as 3/12 = 0.25 feet

3) Multiply the thickness in feet by the square foot area to determine cubic feet of concrete you need such as 1×0.25 = 0.25 cubic feet.

4) convert cubic feet of concrete in cubic yards by dividing by 27 such as 0.25/27 = 0.0185 cubic yards

Thus, you need 0.5 cubic feet or 0.0185 cubic yards of concrete per square foot at 8 inches thick.

**Conclusions:-**

Typically, for a standard 10 cm (4 inches) thick slab, you would need around 0.333 cubic feet or 0.012 cubic yards of concrete per square foot while at 6 inches thick, you would need around 0.5 cubic feet or 0.0185 cubic yards of concrete per square foot.