The Ultimate Concrete Calculator: Find Out How Much CONCRETE You Need

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What is the formula for calculating concrete?

The formula to calculate concrete yardage in cubic yards is as follows:

(length × width × thickness) ÷ 27 = cubic yards

So, you need to measure the length, width, and thickness of the area you want to pour concrete in, and then plug those numbers into this formula to calculate the amount of concrete in cubic yards that you will need.

Let me break it down step-by-step for you!

1. The first step is to convert all the measurements to the same unit, which is feet in this case. So, we have a 10 feet long, 10 feet wide, and 0.33 feet (4 inches) thick slab.
2. Now we need to multiply the three measurements together to get the total volume in cubic feet. So, 10 x 10 x 0.33 = 33 cubic feet.
3. But we need the answer in cubic yards, so we need to divide the cubic feet by 27 (since there are 27 cubic feet in a cubic yard). 33 ÷ 27 = 1.22 cubic yards.

So, the answer is 1.22 cubic yards of concrete needed for a 10' x 10' x 4" thick slab.

Concrete calculator formula for concrete slabs

another example using a formula to calculate cubic yards

To calculate how much concrete you need for a square slab, you need to know the width, length, and depth of the slab.

You can use the formula "Volume in Cubic Feet (ft3) = Width x Length x Depth" to find out the volume of the slab in cubic feet.

Once you have the volume in cubic feet, you can use the formula "Volume in Cubic Yards (yd3) = Volume in Cubic Feet (ft3) / 27" to find the volume in cubic yards, which is what is typically used when ordering concrete.

You can also use the formula "Volume in Cubic Meters (m3) = Volume in Cubic Feet (ft3) x 0.0283" if you need to convert the volume to cubic meters.

For example, if you have a square slab that is 10 feet wide, 10 feet long, and 4 inches deep, you can use the formula to calculate the volume in cubic feet:

Volume in Cubic Feet (ft3) = Width x Length x Depth Volume in Cubic Feet (ft3) = 10 ft x 10 ft x 4/12 ft Volume in Cubic Feet (ft3) = 33.33 ft3

To find the volume in cubic yards, you can use the formula:

Volume in Cubic Yards (yd3) = Volume in Cubic Feet (ft3) / 27 Volume in Cubic Yards (yd3) = 33.33 ft3 / 27 Volume in Cubic Yards (yd3) = 1.23 yd3

So, for this example, you would need to order 1.23 cubic yards of concrete for the slab.

how much concrete do i need for a 24' x 24' slab?

To calculate the volume of cubic yards you'll need for a 24x24 slab, follow these simple steps:

1. Measure the width, length, and depth of the slab in feet.
2. Multiply the width x length x depth to get the volume of the slab in cubic feet.
3. Divide the volume in cubic feet by 27 (the number of cubic feet in one cubic yard of concrete) to get the total cubic yards needed for your slab.
4. To convert the volume of cubic yards to cubic meters, multiply the volume in cubic feet by 0.0283.

For example, if you have a 24' x 24' x 4" thick slab:

1. Multiply 24 x 24 x (4/12) to get 190 cubic feet.
2. Divide 190 by 27 to get 7.04 cubic yards of total concrete needed.
3. Multiply 190 by 0.0283 to get 5.38 cubic meters of total concrete needed.

Remember, there are 27 cubic feet in one cubic yard of concrete (3 x 3 x 3).

LEARN HOW TO POUR YOUR OWN CONCRETE SLAB HERE

Use these free calculators to estimate volume in cubic yards and volume in cubic meters for a specified size on round or circular concrete projects.

Concrete Calculator For Sonotubes, Columns, and Round Slabs

Concrete Calculator For A Doughnut Shaped Slab or Footing

concrete calculator formula for a round slab

The formula to calculate concrete yardage for a round slab is very different than the formula for a square slab.

Square footage (Area) is calculated using Pi and the diameter of the circle to help determine cubic yardage.

Example: Diameter = 20' (feet)  and depth = 4" (inches)

• The area of the circular slab is: π x (diameter/2)^2, where π is approximately 3.14
• So, the area of the 20 ft diameter slab is: 3.14 x (20/2)^2 = 314 ft^2
• To find the volume of the slab, you need to multiply the area by the thickness: 314 ft^2 x 4 inches (converted to feet by dividing by 12) = 104.67 ft^3
• To convert cubic feet to cubic yards, divide by 27: 104.67 ft^3 / 27 = 3.87 cubic yards
• To convert cubic feet to cubic meters, multiply by 0.0283: 104.67 ft^3 x 0.0283 = 2.96 cubic meters

This formula will calculate the volume of a round slab

The formula to find the volume of a round slab in cubic feet is:

Volume = pi x radius^2 x thickness

where pi is approximately equal to 3.14, radius is half the diameter of the slab, and thickness is in feet.

For a round slab with a diameter of 20 feet and a thickness of 4 inches (which is 0.33 feet), the radius would be 10 feet and the formula would be:

Volume = 3.14 x 10^2 x 0.33 Volume = 103.62 cubic feet

To convert this volume into cubic yards, you would divide by 27 (since there are 27 cubic feet in a cubic yard):

Volume in cubic yards = 103.62 / 27 Volume in cubic yards = 3.84 cubic yards

To convert the volume in cubic yards to cubic meters, you would multiply by 0.764554858 (since there are approximately 0.764554858 cubic meters in a cubic yard):

Volume in cubic meters = 3.84 x 0.764554858 Volume in cubic meters = 2.94 cubic meters

calculator formula for a concrete wall

an example of using a formula to calculate concrete for a wall

Let's say we have a concrete wall that is 8 feet tall, 10 feet long, and 8 inches thick. Here's how we can calculate the concrete yardage:

1. Convert the dimensions to feet:

• Height: 8 feet
• Length: 10 feet
• Thickness: 8 inches = 0.67 feet (by dividing 8 inches by 12)

2. Calculate the volume in cubic feet:

• Volume = Height x Length x Thickness
• Volume = 8 feet x 10 feet x 0.67 feet
• Volume = 53.33 cubic feet

3. Convert cubic feet to cubic yards:

• Divide the volume by 27 (since there are 27 cubic feet in 1 cubic yard)
• Cubic yards = 53.33 cubic feet / 27
• Cubic yards = 1.97 cubic yards (rounded to two decimal places)

So we would need approximately 1.97 cubic yards of concrete to build this wall.

Formula to calculate concrete for a footer

Calculating concrete yardage for a footing is done much like a slab, you just usually have smaller units of measurement for width.

Example: Width 18", Depth 8", Length 50' (convert inches to feet)

Volume in Cubic feet = 1.5 x .66 x 50 = 49.5 cubic feet 

Volume in Cubic yards = 49.5 ÷ 27 =  1.83 cubic yards

Volume in cubic meters = 49.5 x .0283 = 1.4 cubic meters

To calculate cubic yardage for a concrete footing, you need to use the following formula:

Volume of concrete in cubic feet (ft3) = Length x Width x Depth

Then, you can convert the volume to cubic yards using the following formula:

Volume in cubic yards (yd3) = Volume in cubic feet (ft3) / 27

Here's an example:

Suppose you need to pour a concrete footing that is 120 feet long, 18 inches wide, and 8 inches deep.

To calculate the cubic yardage of concrete needed for the footing, you would first convert the width and depth from inches to feet by dividing by 12:

Width = 18 inches = 1.5 feet

Depth = 8 inches = 0.67 feet

Now we can plug in the values into the formula:

Volume in Cubic Feet (ft3) = 1.5 feet x 120 feet x 0.67 feet = 120.6 ft3

Volume in Cubic Yards (yd3) = 120.6 ft3 / 27 = 4.47 yd3

Volume in Cubic Meters (m3) = 120.6 ft3 x 0.0283 = 3.41 m3

Therefore, the cubic yardage for the given example of a footing is 4.47 cubic yards.

Concrete calculator formula for a square column

Formula to calculate concrete for a round column

The formula to calculate concrete yardage for a round column is just like the round slab formula above. The difference is a column's height is usually much greater than a slab.

Example: Diameter 3', Height 30'

Area of the circle in square feet is 3.14 x (3÷2)² = 7.065 ft²

Volume in ft³ = 30 (H) x 7.065 (A) = 211.95 ft³

Volume in yd³ = 211.95 ft³ ÷ 27 = 7.85 yd³

Volume in m³ = 211.95 ft³ x .0283 = 5.99 m³ of concrete

How to calculate concrete for steps

This is how you calculate concrete yardage for a set of concrete steps.

Example: Platform Depth 3', Width 6', Run 1', Rise 8".

1st calculate cubic feet for each step. In the example above the first step is:

Run depth = 1' x (Rise height) .66' x 1 (step #1) x 6 (step width) = 3.96 ft³ for step #1

2nd Step is:

Run depth = 1' x (Rise height) .66' x 2 (step #2) x 6 (step width) = 7.92 ft³ for step #2

Platform is:

Platform depth = 3' x (Rise height) .66 x 3 (total steps) x 6 (step width) = 35.64 ft³ for platform

Total cubic feet volume = 35.64 + 7.92 + 3.96 = 47.52 ft³

Cubic yard volume = 47.52 ft³ ÷ 27 = 1.76 yd³ of concrete

Cubic meter volume = 47.52 ft³ x .0283 = 1.34 m³ of concrete

formula to calculate concrete for curbs and gutters

When you use a formula to calculate concrete yardage for curb and gutter, it's very similar to steps.

You break it down into sections and calculate for each section, then add the sections together.

Example: Curb Depth 6", Curb Height 6", Gutter Width 18", Flag Thickness 1', Length 80'

(Convert all dimensions into feet) and calculate cubic feet for each section.

Curb = .5 x (.5 + 1) x 80 = 60 cubic feet

Gutter = 1.5 x 1 x 80 = 120 cubic feet

Total for cubic feet = 180 cubic feet

Cubic yards = cubic feet 180 ÷ 27 = 6.66 yd³ of concrete

Cubic Meters = cubic feet 180 x .0283 = 5.09 m³ of concrete

You can learn more about estimating concrete yardage using my Concrete Calculators