Stone calculator for Delaware

Use this calculator to convert crushed stone from cubic yards to tons. Most grades work out near 2,800 lb for each cubic yard, or 1.4 tons per yard, though the selected material determines the applied weight. It includes twelve graded options, starting with 3/8 inch chips and extending to 2.5 inch railroad ballast. A contractor may begin with a material specification, while a homeowner may start with the project itself. The information below helps connect either starting point to the appropriate stone.

How to calculate

1. For a pad or driveway, calculate feet of length by width. For drains, use trench length multiplied by trench width.
2. Set the depth according to the layer's purpose: 2-3 inches for surface material, 4 inches for base, and 12 inches or more for French drains.
3. Divide cubic feet by 27 for cubic yards. For typical crushed stone, multiply yards by 1.4 to find tons.

Product stone weights

Understanding size numbers

Stone grade numbers refer to rock-size ranges, with the lower numbers representing larger pieces. #4 measures 3/4 to 1-1/2 inches. At 3/16 to 1 inch, #57 is commonly used for drainage, driveways, and concrete jobs. #67 is finer, ranging from 1/4 to 3/4 inch, and is often placed for pipe bedding. #8 is about 3/32 to 3/8 inch, while #89 starts at 3/8 inch and includes fines; these finer grades work in paver joints and finish courses. Screenings combine chips and dust to form a firm bed that can be screeded. Railroad ballast consists of heavy, angular rock from 1 to 2.5 inches, used where drainage and load support are needed below tracks or equipment pads.

Clean stone or fines: choose the right one

For a base, use a blend that includes fines, such as crusher run or road base. After compaction, those fines help it bind together. Drainage calls for washed, clean rock like #57, which stays open so water can move through it. Putting base material in a French drain can leave water sitting there, while a driveway built on #57 alone can continue to shift. When a permit or plan names a gradation, match the material listed. If the material name on the line item is confusing, text it to (302) 406-2968. "3/4 clean" and "#57" may be two names for the same stone.

Common stone order sizes

Example: a 30-foot French drain

Figure the full trench volume rather than subtracting the pipe. At 30 feet long, 12 inches wide, and 12 inches deep, the trench contains 30 cubic feet: 1.1 cubic yards or 1.6 tons of #57. A 4-inch pipe accounts for only about 0.1 yards, so order the full 1.6 tons and place the extra stone at the outfall. Line the trench with non-woven fabric before adding stone to keep soil out of the drainage voids.

Two ways to avoid a wrong stone order

• Begin with the specification and check the local name. Crusher run, crush and run, CR-6, dense graded and GABC describe one material under several names. #57 and "57s" also mean the same stone.
• Plan for 5-10% settling when angular stone is rolled. Use the calculator's extra-percent option for typical settling, but follow the specified compacted depth for engineered base work.
• Paver support comes from compacted base stone, with screenings or concrete sand used above it as a thin leveling layer. On soft ground, dust alone is not a paver bedding material.
• Calculate the trench volume rather than deducting the pipe. Pipes below 6 inches generally displace no more than a wheelbarrow load from the order.

Crushed-stone figures

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