Content

• To step
• Method 1 of 3: Using proportions
• Tips

A cubic foot is a unit of volume. The cubic foot has a length, width and height of one foot (approximately 40 cm). Likewise, a cubic yard is a unit of volume with a length, width, and height of one yard (about 100 cm). These units are often used in the US (because of the imperial system used there) to calculate the volume of gravel, sand and other materials that fill a space. Since feet and yard are both imperial units, the conversion between them is easy.

To step

Method 1 of 3: Using proportions

1. Confirm that you are applying the correct conversion. In this method, you need to know how many cubic feet you have and calculate how many cubic yards that value is. Make sure you work with cubic units (volume) and not square units (area).
   • For example, you can convert 600 cubic feet to cubic yards.
2. Understand the relationship between cubic yards and cubic feet. There are 27 cubic feet in a cubic yard. This means that for every cubic yard, you have 27 cubic feet. You can represent this ratio as follows: ${ displaystyle { frac {1yd ^ {3}} {27ft ^ {3}}}}$Make a comparison. On the left is the ratio for the number of cubic yards to cubic feet. To the right will be the ratio of the number of yards you want to find. Make a fraction with an unknown number of yards in numerator (${ displaystyle x}$Isolate the variable. To do this, multiply each side of the equation by the number of cubic feet you are trying to convert. Multiply the cubic feet by the numerator of the unit ratio to the left of the equation.
   • For instance:
     ${ displaystyle { frac {1yd ^ {3}} {27ft ^ {3}}} = { frac {x} {600ft ^ {3}}}}$Divide the number of cubic feet by 27. This will give you the equivalent number of cubic yards. Note that you can simplify this method by simply dividing the number of cubic feet you have by 27.
     • For instance:
       ${ displaystyle { frac {600yd ^ {3}} {27ft ^ {3}}} = x}$Make sure you are doing the correct conversion. For this method, you start with cubic feet and end with cubic yards. This method does not work for the reverse conversion (cubic yards to cubic feet). Make sure to use cubic units and not square units, because that conversion ratio is different.
     • Calculate the conversion ratio. For every cubic yard, there are 27 cubic feet. This means that one cubic foot is equal to ${ displaystyle { frac {1} {27}}}$Multiply the number of cubic feet by the conversion ratio. This will give you the number of cubic yards that are equivalent to the given number of cubic feet. Since feet are less than yards, you end up with a smaller number for yards than for feet, after the conversion.
       • For example, if you want to convert 600 cubic feet to cubic yards, you calculate ${ displaystyle (600) (0.03703704) = 22.2}$Make sure you convert correctly. In this method, you start with cubic yards and end with cubic feet. If you're dealing with square feet and square yards, this conversion method won't work.
       • Understand the relationship between cubic yards and cubic feet. There are 27 cubic feet in a cubic yard. That means the number of cubic feet is 27 times greater than the equivalent number of yards.
       • Multiply the number of cubic yards by 27. This will give you the number of cubic feet equivalent to the given number of cubic yards. Because the foot is a smaller unit than the yard, the number of feet will be greater than the number of yards.
         • For example, if you want to convert 20 cubic yards to cubic feet, you calculate ${ displaystyle (20) (27) = 540}$. So, 20 cubic yards is equivalent to 540 cubic feet.

Tips

• Many construction project websites have built-in calculators to help you calculate how much concrete you need to fill a given space.
• If you are asked to use the metric system, you will need to convert cubic yards to cubic yards. You do this by dividing the number of yards by 1.3080.