How To Calculate Yardage For Concrete Or Landscaping MaterialsPosted by Eli Larreau
If you are going to pour concrete or fill an area with landscaping materials like dirt or rock, you may need to calculate the yardage. Yardage refers to the volume of materials in cubic yards. We will explain in detail how to calculate yardage. If you understand basically how to do it, but just can’t remember the formula, then you can skip to the bottom of the page for the formula. Otherwise, read this whole article so you understand what the numbers are referring to. It is easier to do the math when you understand what the numbers mean.
First of all, when we say ‘yard’ or ‘yardage’ we mean one cubic yard. That is, 1 yard long by 1 yard wide by 1 yard tall. The formula for calculating volume is V = L x W x H or Volume = length X width X height.
Find the Area in square feet:
We will use a concrete slab pour for our example. Let’s say that we need to figure out the yardage for a slab that will be 15 feet long by 10 feet wide and 4 inches thick. First we find the area by multiplying the length times the width.
- 15 feet X 10 feet = 150 square feet
Find the volume in cubic feet:
So, the area is 150 square feet. Now we need to take this number times the height or the thickness. Our thickness is 4 inches which needs to be converted to feet. To convert from inches to feet you need to take the 4 inches and divide it by 12 inches. We use 12 inches because there are 12 inches in one foot.
- 4 inches / 12 inches = .3333333333 feet or 1/3 of a foot
So, 4 inches is the same as 1/3 of a foot. Now we take the area of 150 square feet times the depth of .3333333333 feet or 1/3 of a foot
- 150 square feet X .333333333 feet = 49.9999999995 (we’ll round that to 50) cubic feet
- Or you can take 150 square feet / 3 (this is the same as 150 X 1/3) = 50 cubic feet
Convert to cubic yards or yardage:
So we have our volume calculated in cubic feet. Now we need to convert from cubic feet to cubic yards. 1 yard is equal to 3 feet. If we convert the length times width times height of one yard into feet we get 3 feet long X 3 feet wide X 3 feet high.
- 3 feet X 3 feet X 3 feet = 27 cubic feet
Now we need to find how many times 27 cubic feet (or 1 cubic yard) fits into the cubic feet of our concrete pour of 50 cubic feet.
- 50 cubic feet / 27 cubic feet = 1.8518518518 cubic yards
That is how you figure out yardage. For a concrete pour you normally have imperfections in the grading that can take up some of your concrete. You don’t want to run out so make sure you order a little extra. Most people order 10-15% more than the exact calculations. If you are using a pump truck you should ask your pump truck company how much extra to order for the pump truck. A pump truck will usually waste at least 1/3 of a yard. Be prepared for this. It is better to have too much than not enough.
What do you do if you have too much concrete? We have a little tip on what you can do with extra concrete.
Okay, so here is the review:
Length in feet X width in feet X height in feet = volume in cubic feet
- 15 X 10 X .3333333333 = 50
Divide the volume in cubic feet by one yard in cubic feet to get the volume in cubic yards or yardage
First calculate the cubic feet, and then divide by 27 to get the yardage.
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