Area (in square feet):
Rectangle: length x width
Right Triangle: 1/2 (length x width)
Circle: radius x radius x 3.14
Mulch Coverage (in cubic yards):
Take the area (in square feet) divided by 100. This equals the number of cubic yards that you will need for a 2-3" depth of mulch coverage.
Ex: Your garden bed is 10' long and 5' wide. Multiply 10 by 5, which equals 50. Then divide 50 by 100, which equals .5. This means that you will need 1/2 cubic yard of mulch to cover the bed at a thickness of 2-3".
**Pine Needle Mulch uses a different coverage rate. One bale covers approximately 25 sq. feet at 2-3" depth.
Rock and Dirt Coverage (in tons):
Take the area (in square feet) divided by 90. This equals the number of tons that you will need for a 2-3" depth of rock coverage.
Example: Your landscaped area is 30' long and 6' wide. Multiply 30 by 6, which equals 180. Then divide 180 by 90, which equals 2. This means that you will need 2 tons of rock to cover the bed at a thickness of 2-3".
For new lawns, gardens, or landscapes: spread 2" of compost over the area, then till or work into the soil to a depth of 6". Use 3/4 cubic yard of compost per 100 square feet.
To refresh established gardens or landscapes: spread 1" of compost over the area, then till or work into the soil if desired. Use 1/3 cubic yard of compost per 100 square feet.
Rock Tonnage in Pond/Stream Construction:
To calculate the amount of boulders needed for a pond, take the pond length x pond width, then divide by 65. This will give you the number of tons you will need.
For streams, you will need 3/4 ton of boulders per 10' of stream length.
To calculate the amount of rock needed for a pond, take the boulder tonnage number calculated above and multiply by .45. This will give you the number of tons of rock you will need (ex. if you need 5 tons of boulders, take 5 x .45. You will need 2.25 tons of rock for your pond).
For streams, you will need 1/2 of rock per 10' of stream length.
Pond Calculations and Pump Sizing:
To calculate volume for an average pond, take the pond width x length x depth. This will equal the area in cubic feet of the pond. Then multiply this number by 7.5 to get the number of gallons in the pond (ex. if your pond is 10' wide by 12' long by 2' deep, take 10 x 12 x 2 = 240 x 7.5 = 1800 gallons).
To determine the pump size needed for your pond, remember that it is best to turn the water in the pond ONCE per hour. Therefore, if your pond is 1800 gallons, you will need a pump that is at least an 1800 gph.
Note: it is best to estimate a little high, or upsize your pump to ensure proper sizing.
* There are 9 bags of mulch (3 cu. ft. bags) per cubic yard.
* One 3 cu. ft. bag of mulch will cover approximately 15 square feet at a 2-3" depth.
* There are 2000 pounds in 1 ton.
* To find the weight of a granite boulder: take its length x width x depth (all in feet) x 180. This equals the weight of the boulder (in pounds).