Concrete Calculator: Figure Out How Much Concrete You Need

Did you know that concrete is the second-most consumed substance in the world behind only water? Over 70 percent of the world's population live in a structure that contains concrete. This is because concrete is strong, versatile, and plentiful.  

Concrete flooring is the most common application within the home, usually a patio, walkway, or garage floor. Whether you're installing a new floor or replacing an old one, you'll need a good concrete calculator to ensure you have the right amount for the job.

The formula is a simple one, yet there are several other factors to consider that will impact your calculations.

What Is the Correct Concrete Calculator Formula?

Online concrete calculators can be very helpful in this process. The correct concrete calculator formula is you solve for volume or length x width x depth. However, you are usually measuring in feet, yet the standard measurement for concrete is by the cubic yard, so you'll have to do a little math. Make sure you have a calculator on hand when estimating a job. You can download a concrete volume calculator concrete cost calculator to your smart device to make this even easier.

Let's use a 10-foot square with a four-inch thickness as an example. You would multiply the 10-foot square giving you 100 feet of surface area. Convert your four-inch depth to feet (inches/12) and you get 0.33 feet. Multiply your depth by your surface area (0.33 x 100) and you get 33 cubic feet. Multiply that by 0.37 and you arrive at your cubic yard total, 1.22 in this case. 

You want to be sure to add at least 10 percent for spillage and uneven surfaces. This will avoid costly surcharges for partial orders and you don't want cure lines from different batches of concrete.

What Type of Concrete Should I Use?

There are some variables to consider before buying concrete. One important one is how strong you need it to be. This is dependent upon where and how you use it. On average your concrete is around 3,000 psi, but it can go as high as 20,000 psi. Garages and driveways will need to support the weight of vehicles so they should be stronger than say a back patio or lanai which will only support people.

How fast your concrete sets are another consideration. Quick set concrete will set in 20 to 40 minutes and is good for small jobs. Regular set concrete will harden in 24 to 48 hours. This will give you time to complete larger jobs before it hardens. High-strength concrete usually sets in 10 to 12 hours and is typically used in foundation slabs.

You might want to use crack-resistant concrete, especially when durability counts like on walkways and other high traffic areas. If you have heat or other weather issues you should consider a polymer style that uses epoxy to harden the concrete. You'll also want a good concrete sealer for some applications.

Should I Use Ready-Mix or Bagged Concrete?

Both options provide you with the same result, a concrete floor. Yet there are pros and cons to each you need to consider.

Ready-Mix Pros

Having a concrete supplier show up with a truckload of concrete is the easiest way to get your concrete. It arrives ready to pour for quick installation. Ready-Mix is ideal for larger jobs like garage floors, foundation slabs, parking lots, concrete pools, patios, commercial sidewalks, and driveways.                                                 

Most ready-mix suppliers will come to your job site, which can save you headaches in the long run. They will take a look at the sight and offer advice on how much you need and any other special requirements they may have that you might not have considered.

Ready-Mix Cons

A concrete truck holds anywhere from nine to eleven yards. To begin, most suppliers will require a minimum, usually at least one yard. You want to be certain you know how to calculate concrete correctly. If you miscalculate you will end up being charged a shortage fee for ordering a partial batch. Thus, there is a necessity for more waste with ready-mix.

Bagged Concrete Pros

There is very little waste when mixing by the bag. It's also great for smaller jobs like a walkway, setting fence posts, repairing walls and foundations, deck footings, and small curbs and steps.

Bagged Concrete Cons

Mixing by the bag usually means you'll have to pick up the bags and transport them yourself. You'll also need a way to mix them, either with a mixer or in a wheelbarrow. Once mixed, you'll need to move the concrete yourself too, a physically difficult task.

What Tools Should I Have?

You'll want to be sure you have everything you need before you start pouring your concrete. The tools you'll need will depend largely on the type of concrete you're using and what you're building. If you're mixing and moving the concrete yourself you'll want several wheelbarrows, and maybe even a mixer.

Finish trowels and brushes are also necessary, and you'll want the right size for the job. Some repair work requires a concrete grinder or polisher. Sealant sprayers are another worthwhile investment.

How Can I Calculate the Cost?

The cost of concrete can vary widely depending on your location and how much you need. Buying in bulk will save you in the price per cubic yard, simply because the fixed cost to deliver two yards is the same as 10 yards. Therefore there isn't a single concrete price calculator you can use. You'll have to do your measurements and contact different suppliers to get an estimate.

Generally speaking, you can expect to pay between $140 to $200 for one cubic yard of ready-mix concrete. A full load at 10 cubic yards will run between $1,000 and $1,300, which is cheaper because the fixed costs are spread out more. 

You'll want to discuss any additional fees you might encounter with your concrete supplier. Often smaller loads will have short load fees attached, further increasing your cost. Weekend deliveries often come with a surcharge too.

Partner With A Concrete Professional 

Using a concrete calculator to estimate your next job should be easy, as long as you follow the above advice. There are many aspects to working with concrete in addition to simply pouring fresh slabs. 

On Floor Technologies is the leading manufacturer of planetary resurfacing and restoration tools. We are here to help with all of your concrete needs, from pouring to repairing. You can contact us to schedule a demonstration and one of our professionals will take you through our product line and show you the best machine for your next project.