Stone calculator for Rhode Island

Most crushed stone is purchased by the ton. Across the usual grades, a cubic yard is about 2,800 lb, which works out to 1.4 tons per yard. This calculator uses the selected material's weight for each of the twelve graded products, covering 3/8 inch chips through 2.5 inch railroad ballast. A contractor may begin with a specification, while a homeowner may begin with the work at hand. The guide below connects both to the appropriate stone.

How to calculate

1. For the area in feet, calculate length times width on a driveway or pad. For a drain, multiply trench length by trench width.
2. Layer purpose determines depth: use 2 to 3 inches for top courses, 4 inches for bases, and 12 inches or more for French drains.
3. Divide cubic feet by 27 to get cubic yards. For typical crushed stone, multiply yards by 1.4 to find tons.

Product stone weights

Understanding stone sizes

Stone grade numbers identify size ranges, with a lower number generally indicating larger pieces. #4 ranges from 3/4 to 1-1/2 inches. At 3/16 to 1 inch, #57 is used for drainage, driveways, and concrete work. #67 is smaller, measuring 1/4 to 3/4 inch, and is commonly placed around pipe. #8 is about 3/32 to 3/8 inch, while #89 goes from 3/8 inch down to fines. These finer grades are used for paver joints and finish layers. Screenings contain dust and small chips, forming a compactable bed for screeding. Heavy, angular railroad ballast measures 1 to 2.5 inches and provides drainage and load support below tracks and equipment pads.

Clean stone or fines: choose the right type

Stone on this page generally falls into 2 groups. Washed, clean material such as #57 remains open and lets water through, making it suited to drainage. Crusher run, road base, and other mixes containing fines compact into a firm layer, which is why they belong under bases. Using the wrong type causes trouble: crusher run in a French drain can trap water, while a #57 driveway base can keep moving. On Rhode Island lots, route drainage toward the planned dry well instead of a neighbouring property. When a plan or permit lists a gradation, order the stated material. If the name is confusing, text the line item to (401) 210-4557; "3/4 clean" may also be called "#57".

Common stone quantities

Example: a 30-foot French drain

A 30 feet long trench that is 12 inches wide and 12 inches deep has 30 cubic feet of volume. That comes to 1.1 cubic yards, or 1.6 tons of #57. A 4-inch pipe placed in the trench accounts for only about 0.1 yards, so purchase the full 1.6 tons and put the small remainder at the outfall. Line the trench with non-woven fabric before placing stone so soil does not fill the drainage spaces.

Two ways to avoid ordering mistakes

• Use the specification first, then check the local name. Crusher run, crush and run, Bank Run Gravel, gravel borrow, and pit gravel can describe one product under several names. #57 and "57s" refer to the same stone.
• Rolled angular stone can compact by 5 to 10%. Use the calculator's extra-percent toggle for typical settling. For engineered base work, use the specified compacted depth.
• Pavers need compacted base stone for support, then a thin leveling layer of screenings or concrete sand. Do not set pavers on dust alone where the ground is soft.
• Base the calculation on the whole trench rather than deducting the pipe. A pipe below 6 inches usually displaces less than a wheelbarrow load.

Crushed stone facts and figures

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