How to Estimate Concrete for a Pore

Pouring concrete

Correctly estimating the amount of concrete you need for a project is a fairly simple task, but an important one. If you estimate too high you will have extra concrete that you will have to pay for and dispose of when finished. At about $70 per cubic yard, this can quickly become an expensive mistake. If you estimate too low, the problem is the concrete you pour may become hard before you can get more. This is bad because the concrete will not form together and can break or leak at this seam.

Things You'll Need

• tape measure
• calculator

Instructions

1. 

   Measure

   Defining the unit of measurement is the first step. Typically, concrete is sold in cubic yards. A cubic yard is the three-dimensional measurement of where you are going to pour the concrete. As an example, if you are pouring a concrete slab for a building to sit on you would measure the width, length, and thickness you want the slab to be. A cubic yard is one yard times one yard times one yard.

2. 

   Convert and Calculate

   Measuring is the most important step. Start by measuring the width of what you plan to fill. Then measure the length. Finish by measuring how deep you want to pour the concrete. If you are pouring a slab, then the measurement might be something like 15 feet by 20 feet by 4 inches.

3. 

   Round Up

   Start by converting your measurements into one standard form of measurement. In the above example we have both feet and inches. It is probably easiest to convert everything to inches in this case. There are 12 inches in a foot so you would take 15 feet times 12 inches which gives you 180 inches. Repeat this calculation for the length, namely 20 feet times 12 inches, or 240. Now you have 180 inches times 240 inches times 4 inches (length x width x depth). This gives you 172,800 cubic inches. A cubic yard is 36 inches wide by 36 inches long by 36 inches deep. Take the cubic inches you calculated, in this case, 172,800, and divide it by 36 three times. What you end up with in this case is 3.7 cubic yards.

4. 

   Concrete Calculators

   Running out of concrete before you have filled your space is not a good situation to be in. Therefore, it is always a good idea to have a little extra on hand. Rule of thumb is to add about 10 percent to the order. In this case it would make sense to round to an even 4 cubic yards.

5. 

   Calculating the amount of concrete you need is fairly straight forward, but if you are not comfortable with math there are several on-line calculators that you can use. Several sites are given in the Reference section of this article.

References

• How Much Concrete Do You Need?
• To Estimate the Amount of Concrete Needed