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How to Calculate Compost Coverage

Compost is one of the most valuable garden materials available and can improve nearly any type of garden. Not only does it provide valuable nutrients without the use of chemicals, it also helps loosen soil, prevents soil compaction, retains moisture and provides winter protection for tender plants. Compost also reduces the amount of work needed to maintain a garden, flower bed or lawn by helping keep weeds down. Using the right amount of compost is the key to ensuring plants receive all the benefits it has to offer.

Measure the length and width of the area where you plan to spread the compost.

Multiply the length by the width to determine the square footage of the area you plan to cover.

Decide how deep you want the compost to be spread. Chittenden County Solid Waste District of Virginia recommends spreading compost between 1 and 3 inches deep in vegetable gardens or for covering crops or plants over the winter, and one-fourth to one-half-inch thick on grass lawns or in flower containers or raised beds.

Multiply the square footage that you determined in steps 1 and 2 by the depth of compost that you chose in Step 3.

Multiply the number you arrived at in Step 4 by .0031. For example, if the area you are covering measures 5 feet by 5 feet, or a total of 25 square feet, and you want the compost to be 2 inches deep, you would multiply 25 by 2, and then multiply the result by .0031. The resulting number is the amount of cubic yards of compost required to cover the area to the desired depth.


Use more compost in cold areas or where soil condition is poor, and less in areas where the soil is rich or with mild winters.


Don't worry too much about being off a few inches, or getting exact measurements of odd shapes. Simply round the numbers up to determine the amount of compost needed. Because compost will not spread exactly even, estimating the amount needed is acceptable.

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