When pouring concrete for any application, it is important to plan ahead and determine what materials are needed to complete the job. However, knowing how to calculate the amount of concrete needed can be a challenge, especially for new pourers. Learn more about the concrete formula and how to apply it.

What Is the Concrete Formula?

The concrete formula is a mathematical formula used to determine how much concrete is needed to fill a particular area or complete a job. Like many materials used in construction, concrete is sold and measured in cubic yards. The concrete formula is: 

Length (in feet) x width (in feet) x height (in feet) / 27 = number of cubic yards needed

For example, if a construction company was pouring concrete over a site that measured 100 feet in length by 50 feet in width by 2 feet in height, that site would need 371 cubic yards of concrete to tackle that job. (100 x 50 x 2 / 27 = 370.37, rounded up to 371.) If another company was pouring concrete footings into a space measuring 20 feet (length) x 1 foot (width) x 2 feet (height), the number of cubic yards needed would be 1.48.  

Using the concrete formula or a concrete calculator helps to take the guesswork out of concrete pouring.

cement pouring

What Is Reinforced Concrete (RCC)?

Reinforced concrete includes steel rods, mesh, or bars embedded into the material, allowing the two to resist one another to build strength. The steel portions absorb the shear, tensile, and compressive stresses in a concrete structure, as concrete alone cannot withstand these forces when caused by heavy vibrations, wind, or earthquakes. Reinforced concrete was invented in the 19th century, revolutionizing the construction world and quickly becoming one of the most commonly used forms of concrete. When using reinforced concrete, the steel mesh, rods, or bars are placed first and filled in or covered up with concrete.

How Do You Calculate RCC?

Since reinforced concrete includes the material surrounding the steel pieces, the calculation is slightly different. Construction managers may also need to calculate how much steel or rebar is needed to complete the job. Other calculations to consider include the spacing of the bars and the volume of the slab being poured, all of which will factor into the proper calculation. Various calculators are available online. 

Ready-Mix vs. Bagged Concrete

Another consideration is whether a project manager will choose ready-mix or bagged concrete. Ready-mix concrete is manufactured in a batch plant and delivered to the construction site. It’s designed for sites where mixing the concrete is not feasible or those working on the site do not want to mix it themselves. It is measured and sold by volume and includes a blend of cement, water, and aggregates, such as crushed stone, gravel, or sand.

Bagged concrete is similar to ready-mix, although it may not be quite as strong as ready-mix options. It requires the addition of water and must be mixed by the person pouring it in order to be ready for placement on a job site.

At NTS Contractors, we’re experts in all things concrete. Our experienced technicians can pour concrete and perform repairs, as well as tackle striping, power washing, sandblasting, and other concrete-related needs. Contact us to learn more or if you would like to request an estimate.