Gravel is a classification of small crushed rock that is used commercially in a variety of projects. When working with commercial gravel, finding the tonnage of gravel is a simple calculation that requires only the dimensions of the area and the weight of the gravel. This is true whether you are attempting to purchase the right amount of gravel for a walkway on your property or calculating the estimated weight of the gravel you wish to remove from an area.
Things You'll Need
 Tape measure
 Calculator (optional)

Measure the length and width of the area the gravel will be poured in or removed from.

Convert the length to yards, if you used a different unit of measure, by dividing by 3 if you measured in feet or 36 if you measured in inches.

Multiply the length in yards by the width in yards to find the surface area of the project area in square yards.

Measure the depth of the area the gravel will be poured, or estimate the depth if you are removing gravel and cannot accurately measure the depth.

Convert the depth to yards if needed, then multiply the depth by the surface area to find the cubic yards of gravel.

Multiply the volume, or total cubic yards, by 1.35 to find the number of tons, as a cubic yard weighs approximately 2,700 pounds, or 1.35 tons.
References
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