How Much Material Do You Need?

Irregular areas

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″