How to Calculate How Much Gravel I Need

Gravel can be used for mulch, to make an attractive border, a walkway or as a base for other projects. Available in a variety of colors from gray to light brown, gravel can be purchased from a wide range of home and garden stores as well a bulk material companies. Calculating the amount of gravel needed is an important first step to determine how much gravel you should purchase to accomplish the job.

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Measure the length and width of the area where the gravel will be placed. Use a tape measure and determine the overall length of the area as well as the width.

Step 2

Measure odd-shaped areas by breaking them down into rough rectangular or square shapes.

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Multiply the length by the width to determine the square footage.

Multiply the length by the width to determine the square footage. Use a calculator to perform the multiplication if necessary. For example, multiply a length of 12 by a width of 10 to equal 120 square feet.

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Determine how many inches of gravel will be placed in the area. Multiply the total number of inches for the gravel depth by the total square feet from the previous step. For example, using a gravel depth of 3 inches, convert the inches to feet, which equals 0.25. Multiply 120 square feet by a gravel depth of 0.25 feet to equal a volume of 30 cubic feet.

Step 5

Divide the total cubic feet, using the example of 30, by 27 to convert the amount to cubic yards. Use the cubic yards figure when purchasing in bulk, as most landscaping materials are sold by the cubic yard. For the example of 30 cubic feet needed, divide by 27 to equal 1.11 cubic yards.