Crushed Stone Calculator
Enter the dimensions of your project area, select the type of crushed stone, and set a waste factor to calculate the volume in cubic yards, weight in tons, and number of 50-lb bags needed.
Estimate only — not professional advice. Always verify results independently before purchasing materials or beginning work. Terms of Use
What is Crushed Stone?
A crushed stone calculator determines how much stone material you need for driveways, walkways, drainage beds, retaining wall backfill, and other hardscape projects. Crushed stone differs from natural gravel in that it is mechanically broken from larger rock and has angular edges that interlock when compacted, providing a more stable base than rounded natural gravel. The calculation converts your project dimensions into cubic yards of material, then converts to weight using the density of the specific stone type. Different stone materials have different densities. Limestone is one of the most common crushed stones, weighing approximately 1.5 tons per cubic yard. Granite is slightly lighter at 1.4 tons per cubic yard due to its mineral composition. Trap rock (basalt) is the densest common option at 1.6 tons per cubic yard, making it excellent for high-traffic areas and road bases. Recycled crushed concrete is the lightest at 1.3 tons per cubic yard and is an economical, environmentally friendly alternative for sub-base applications. The waste factor accounts for material lost during delivery, spreading, and compaction. Crushed stone compresses 10 to 15 percent during compaction with a plate compactor or roller, and some material is always lost to uneven ground, edge spillover, and truck residue. A 10 percent waste factor is standard for most residential projects. Increase to 15 percent for areas with soft or uneven soil where stone may settle into the ground, or for projects requiring mechanical compaction to a specific density. For small projects and repairs, crushed stone is available in 50-pound bags at home improvement stores. Each bag contains approximately 0.5 cubic feet of material. The bag count output helps you determine whether bagged stone is practical for your project or if a bulk delivery is more economical. As a rule of thumb, bulk delivery becomes more cost-effective above 1 to 2 cubic yards. Common crushed stone sizes are classified by number. No. 57 stone (3/4 inch) is the most versatile for driveways, drainage, and backfill. No. 411 (a blend of No. 4 and stone dust) compacts into a solid surface for paths and patios. No. 2 stone (2-3 inches) is used for heavy drainage and erosion control. The size you choose does not significantly affect weight calculations because density is primarily determined by the parent rock material.
How to Calculate
- Measure the length of the project area in feet
- Measure the width of the area in feet
- Determine the desired depth of crushed stone in inches (4 inches for driveways, 2-3 inches for walkways, 6+ inches for road bases)
- Select the type of crushed stone you plan to use
- Set the waste factor (10% is standard, 15% for compacted bases)
- Review the cubic yards and tonnage for bulk ordering, or the bag count for small projects
- Contact your local quarry or supplier with the tonnage figure for pricing
Formula
Area = Length (ft) x Width (ft) Cubic Feet = Area x Depth (in) / 12 Cubic Yards (raw) = Cubic Feet / 27 Volume with Waste = Cubic Yards x (1 + Waste Factor / 100) Weight = Volume x Stone Density (tons per cubic yard) Density: Limestone = 1.5, Granite = 1.4, Trap Rock = 1.6, Recycled Concrete = 1.3 50-lb Bags = ceiling(Volume x 27 / 0.5) The depth is divided by 12 to convert inches to feet. Volume in cubic feet is divided by 27 to convert to cubic yards. Each 50-lb bag holds approximately 0.5 cubic feet of crushed stone.
Example Calculation
A 20 ft x 10 ft driveway area, 4 inches deep, limestone, 10% waste: Area = 20 x 10 = 200 sq ft Cubic Feet = 200 x (4 / 12) = 66.67 cu ft Cubic Yards (raw) = 66.67 / 27 = 2.47 cu yd With 10% waste = 2.47 x 1.10 = 2.72 cu yd Weight = 2.716 x 1.5 = 4.07 tons (using unrounded volume) 50-lb Bags = ceil(2.72 x 27 / 0.5) = ceil(146.88) = 147 bags
Frequently Asked Questions
How deep should crushed stone be for a driveway?
A residential driveway typically needs 4-6 inches of compacted crushed stone over a prepared sub-grade. The stone is usually placed in two lifts: 3-4 inches of coarser base stone (No. 2 or No. 57) compacted first, then 2 inches of finer stone (No. 411 or stone dust) compacted on top for a smooth driving surface.
What is the difference between crushed stone and gravel?
Crushed stone is mechanically broken rock with angular, irregular edges that interlock when compacted, creating a stable surface. Gravel is naturally rounded from water erosion and does not lock together as well. Crushed stone is preferred for structural bases, while rounded gravel is used for decorative applications and drainage where compaction is not required.
Should I order by the cubic yard or by the ton?
Ordering by the ton is more precise because volume can vary with moisture content and how loosely the stone is loaded. Most quarries sell by the ton using calibrated truck scales. Use the tonnage output from this calculator for your order, and keep the cubic yard figure for planning how much space the delivery will occupy.
How many bags of crushed stone are in a cubic yard?
At 0.5 cubic feet per 50-lb bag, one cubic yard (27 cubic feet) requires 54 bags. That is 2,700 pounds or 1.35 tons of bagged material. Buying bags at retail prices is typically 3-5 times more expensive per ton than bulk delivery, so bags are only economical for small patches and repairs.
Do I need to compact crushed stone?
Yes, for any structural application like driveways, patios, or building pads. Compact in lifts of 3-4 inches maximum thickness using a plate compactor. Each lift should be moistened slightly before compaction. Uncompacted crushed stone will shift and settle unevenly under load, causing ruts and surface failures.
What size crushed stone should I use?
No. 57 stone (3/4 inch) is the most common all-purpose size for driveways, drainage, and backfill. No. 411 (crushed stone with fines) compacts into a solid surface for walkways. No. 2 stone (2-3 inches) handles heavy drainage. Stone dust or screenings (1/4 inch minus) works for leveling paver and flagstone beds.