How Much Material Do You Need?

For estimating quantity needed for irregular areas break the area up into smaller workable shapes. Measure each of them and assign them a letter. Calculate square feet for each and add the square footage together to figure total needed.

Rectangle

• Measure Length and Width (in feet)
• Length x Width = square feet
• Determine desired depth of material (see recommended depths and chart below)
• Square feet divided by sq. ft. per yard (from chart) = cubic yards needed
• Example: A rectangular area 16 feet long by 10 feet wide and you want 4 inches deep of stone.
• Calculations:
• 16 x 10 = 160 square feet
• 160 divided by 81 = 2 cubic yards (81 comes from the chart, 81 is how many square feet 1 cubic yard covers at a 4 inch depth)

Triangle

• Measure length and width of 2 sides
• Length x Width x 0.5 = square feet
• Square feet divided by sq. ft. per yard (from chart) = cubic yards needed
• Example: Given a triangle are where one side is 40 feet long, one side is 10 feet long and you want 4 inches deep of mulch or stone
• Calculations:
• 40 x 10 x 0.5 = 200 square feet
• 200 divided by 81 = 2.5 cubic yards (81 comes from the chart)

Circle

• Determine radius (1/2 distance of diameter or distance across)
• Formula: Radius x Radius x 3.14 = square feet
• Square feet divided by sq. ft. per yard (from chart) = cubic yards needed
• Example: Given a circle 30 feet across (15 ft radius) and you want 3 inches deep
• Calculations:
• 15 x 15 x 3.14 = 706.5 square feet
• 706.5 divided by 108 = 6.5 cubic yards 

Conversion Chart – Square Feet to Cubic Yards

Converts square feet to cubic yards 1 cubic yard will cover the following amount of square feet at the given depth.

• 1/4” deep 1296 square feet
• 1” deep 324 square feet
• 2” deep 162 square feet
• 3” deep 108 square feet
• 4” deep 81 square feet
• 6” deep 54 square feet
• 12” deep 27 square feet 

Recommended Depth of Materials

• Bark Mulches 3”
• Stone less than 1" diameter 3"
• 1-1 1/2" Riverstone 4"
• Soil for Lush Lawns 4+"
• Garden Soil in Flower Beds 6-12"
• Lawn topdressing 1/4"
• Pathways 4" 

Volume Fun Facts

• There are 54 50lb bags of stone or sand per cubic yard.
• 27 cubic feet equal 1 cubic yard (3'L x 3'W x 3'H).
• Soil weighs about 2,200 lbs per cubic yard.
• Stone weighs about 2,700 lbs per cubic yard.
• Mulch weighs 250-750 lbs per cubic yard.
• Full size pick-up with 8’ box a heaping load is 3 cubic yards.
• Small size pick-up heaping load is 1 ½ cubic yards.
• Typically a full size truck can take ½ - 1 cubic yard stone or soil.
• Typically a small pickup truck can take ⅓ - ½ cubic yard stone or soil.
• 7 to 12 wheel barrow loads in 1 cubic yard.
• When topdressing previously mulched beds you only need to add enough mulch to existing bed to get a total of 3".
• Installing less than the recommended amounts of stone can result in OK short term appearance but after a few years the stones somehow disappear and the ground reappears.