Calculating Cubic Yards

Follow the steps below to determine how many cubic yards of landscaping material (mulch, rock, etc.) you will need to complete your project.

  1. Calculate the square footage of the area to be covered:
    Length x Width = Square Feet
  2. Decide how thick you want your cover to be, and use the chart below to get your
    Desired Thickness Variable 

  3. Use the outputs from Steps 1 and 2 to calculate the cubic yards required:
    Square Feet ÷ Desired Thickness Variable = Cubic Yards


Your flowerbed is 15’ long by 12’ wide, and you want to lay 3” of mulch.  Using the steps we just learned…

  1. 15’ x 12” = 180 sq. ft.
  2. Desired Thickness Variable for 3” is 100
  3. 180 ÷ 100 = 1.8 cu. yd.

1.8 cubic yards will be sufficient to cover your flowerbed.  To be safe, it’s wise to round up to the next whole number, especially if you’re buying bagged mulch.  See the conversion chart below for bagged materials.

Buying Pre-Bagged Materials

Use the chart below to determine how many bags of material you will need to cover your calculated cubic yards. 

Pre-Bagged Materials3 cu. ft. bags, 9 bags = 1 cubic yard

2 cu. ft. bags, 13.5 bags = 1 cubic yard  

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