Do you have a concrete pour project on the way, but you don’t know how to do the math involved? Or maybe you just want to refresh your memory from school days?
It’s always good to make sure you’re on the right track when uncertain. Planning the budget and calculating everything costs might be the most important thing in big projects like this.
Without proper planning, you might run out of money at a critical moment, and then your slab might be on the stage where there are boards on the ground, but no concrete. Or there might be a slab on the ground, but nothing to build on top of it.
Now, that is just an extreme example, but I do know few cases where outside influence paused a project midway. So it’s reality sometimes.
Calculating concrete yardage
It’s important to know how to calculate concrete yardage when bigger projects are on the schedule and you want to know how much it will the concrete cost. You can also use this example to calculate cubic yards for fill dirt, rock, and sand for other home improvement projects. The proper calculation will help with quality control as well.
Step 1: As always, the first thing is measuring and planning. If you are replacing an existing patio, sidewalk, or other space, use a measuring tape. If you are creating a new project, draw a plan and write the intended dimensions on it. It would be good to do some in place measuring as well to be sure everything will fall in with the plan.
Step 2: Convert the dimensions from inches into yards by dividing the inches by 36. (There are 36 inches in a linear yard.)
Step 3: Calculate the area by multiplying the width and length of the space in yards.
TIP: Multiplying width and length to determine the area will only work with rectangular areas. If you have an odd-shaped area, draw a plan that reflects the area, then use a ruler to break up the plan into standard shapes such as triangles, circles, and rectangles.
Then calculate the area of each individual shape and add the area of each space together for a total area.
Step 4: Determine the depth of the concrete pad. In most cases, 4 inches is standard. However, this can vary depending on the application.
Step 5: Divide the depth of the concrete pad by 36. You should get a fraction or decimal number. (For instance, if you use a 4 inch depth, it is also 1/9 of a linear yard.)
Step 6: Multiply the depth of the concrete pad by the area of the space you intend to cover. This will give you the amount of concrete you need in cubic yards.
Once you have the correct number of cubic yards, you may want to check your calculations using a cubic yard concrete calculator online. Also, try adding 10 percent more to your cubic yard calculations. This will help account for any loss during the mixing and pouring process.
TIP: To add 10 percent more to your calculations, multiply your cubic yard calculations by 1.1 or 11/10. The resulting number will be 10 percent more than you should theoretically need to finish your concrete project.
How much is a cubic yard of concrete?
The first calculation is to determine how many cubic inches are in a cubic yard. This is done by multiplying the height times the width times the depth of a cubic yard. This calculation will tell you there are 46,656 cubic inches in a cubic yard. (36 x 36 x 36 = 46,656)
The next number you will need to find is how much concrete it will take to cover a square foot of patio 4 inches deep. This is done in the same way we calculated the cubic yard. Height times width times depth. (12 x 12 x 4 = 576) For every square foot of concrete four inches deep you will need 576 cubic inches of concrete. You now have two of your four numbers needed.
The next calculation is a simple one. Take the total cubic inches in a cubic yard and divide it by the number of cubic inches needed to cover a square foot. 46,656 divided by 576 = 81 square feet covered per cubic yard.
Recap of calculation:
One cubic yard = 46,656 cubic inches (36 x 36 x 36)
Each Square foot requires 576 cubic inches (12 x 12 x 4)
One cubic yard of concrete will cover 81 square feet at a depth of 4 inches
This is how to calculate concrete yardage and how much is cubic yards of concrete as well. Don’t know if it helps, but I do hope so.
Estimation is always the hard part and most of the time when we plan big projects like stucco exteriors we add 10% on calculations to avoid errors and other failures.
There might be an accident on the pour or someone could have calculated wrong. There are many things that could go wrong and 10% is a good fail-safe and usually, it’s enough.
Now, something like a concrete slab should be easy to estimate, and in the same way you can start calculating walls as well. You just measure the same dimensions as before minus the doors and windows.
The ceiling is, if made out of concrete, is basically another slab again. You can get quite far with this basic math.