Crush and Run Calculator
Estimate the amount of crush and run gravel needed for your project (driveway, base, etc.). Enter the dimensions and desired depth.
What is Crush and Run?
Crush and run, also known as crusher run, quarry process (QP), or dense grade aggregate (DGA), is a type of gravel made from crushed stone, screenings, and stone dust. It’s a mixture of different-sized angular stones and fines, which allows it to compact tightly and form a very stable, interlocking base. This makes it an excellent base material for driveways, patios, walkways, roads, and under concrete slabs or pavers. The fines fill the voids between the larger stones, creating a dense and robust layer. Our crush and run calculator helps you determine the amount you need.
Anyone undertaking a landscaping or construction project requiring a solid base layer should use a crush and run calculator. This includes homeowners building a driveway, contractors laying a foundation, or landscapers installing a patio. Accurately calculating the amount prevents over-ordering (wasting money and material) or under-ordering (causing delays and extra delivery charges).
A common misconception is that all gravel is the same. Crush and run is specifically designed for compaction and stability, unlike decorative round river rock or pea gravel, which don’t interlock well and are unsuitable as a base.
Crush and Run Calculator Formula and Mathematical Explanation
The crush and run calculator uses a series of steps to estimate the required amount:
- Convert Depth to Feet: The depth is usually given in inches, so it’s converted to feet: `Depth (ft) = Depth (in) / 12`.
- Calculate Base Volume: The volume of the area without considering wastage is calculated: `Base Volume (cubic feet) = Length (ft) × Width (ft) × Depth (ft)`.
- Convert to Cubic Yards: Since gravel is often sold by the cubic yard, we convert: `Base Volume (cubic yards) = Base Volume (cubic feet) / 27`.
- Calculate Wastage Amount: A percentage for wastage is added: `Wastage Amount (cubic feet) = Base Volume (cubic feet) × (Wastage (%) / 100)`.
- Calculate Total Volume: The wastage is added to the base volume: `Total Volume (cubic feet) = Base Volume (cubic feet) + Wastage Amount (cubic feet)`. Also in cubic yards: `Total Volume (cubic yards) = Total Volume (cubic feet) / 27`.
- Calculate Total Weight: Using the material’s density, the weight is found: `Total Weight (lbs) = Total Volume (cubic feet) × Density (lbs/cubic foot)`.
- Convert Weight to Tons: Weight is often measured in tons (US short tons): `Total Weight (tons) = Total Weight (lbs) / 2000`.
The crush and run calculator performs these calculations to give you the total tons or cubic yards needed.
| Variable | Meaning | Unit | Typical Range |
|---|---|---|---|
| Length (L) | Length of the area | feet (ft) | 1 – 1000+ |
| Width (W) | Width of the area | feet (ft) | 1 – 100+ |
| Depth (D) | Desired thickness of the layer | inches (in) | 2 – 12 |
| Density | Weight per unit volume of crush and run | lbs/cubic foot | 110 – 130 |
| Wastage | Extra percentage for unevenness, etc. | % | 0 – 20 |
Practical Examples (Real-World Use Cases)
Example 1: Driveway Base
John is building a new driveway that is 50 feet long and 12 feet wide. He wants a 6-inch deep base of crush and run. He estimates a 10% wastage and uses a density of 120 lbs/ft³.
- Length = 50 ft
- Width = 12 ft
- Depth = 6 inches
- Wastage = 10%
- Density = 120 lbs/ft³
Using the crush and run calculator:
- Base Volume = 50 * 12 * (6/12) = 300 cubic feet = 11.11 cubic yards
- Total Volume (with 10% wastage) = 330 cubic feet = 12.22 cubic yards
- Total Weight = 330 * 120 = 39600 lbs = 19.8 tons
John needs approximately 12.22 cubic yards or 19.8 tons of crush and run.
Example 2: Patio Base
Sarah is preparing a base for a 15 feet by 15 feet patio. She needs a 4-inch deep layer of crush and run. She anticipates 5% wastage and the supplier’s crush and run has a density of 115 lbs/ft³.
- Length = 15 ft
- Width = 15 ft
- Depth = 4 inches
- Wastage = 5%
- Density = 115 lbs/ft³
The crush and run calculator shows:
- Base Volume = 15 * 15 * (4/12) = 75 cubic feet = 2.78 cubic yards
- Total Volume (with 5% wastage) = 78.75 cubic feet = 2.92 cubic yards
- Total Weight = 78.75 * 115 = 9056.25 lbs = 4.53 tons
Sarah should order about 2.92 cubic yards or 4.53 tons.
How to Use This Crush and Run Calculator
- Enter Dimensions: Input the Length and Width of the area you need to cover in feet.
- Specify Depth: Enter the desired Depth (thickness) of the crush and run layer in inches.
- Material Density: Input the density of the crush and run material in pounds per cubic foot (lbs/ft³). The default of 120 is a good average for compacted material, but check with your supplier if possible.
- Add Wastage: Enter a wastage percentage to account for uneven ground or compaction. 5-10% is typical.
- Calculate: The calculator automatically updates, or click “Calculate”.
- Review Results: The calculator will show the total tons and cubic yards of crush and run needed, including wastage, as well as intermediate values. The chart and table provide further insights.
The primary result tells you the total amount to order. The intermediate results help you understand the base volume before wastage. The chart visually breaks down the volume components, and the table shows how different wastage percentages affect the total amount.
Key Factors That Affect Crush and Run Results
- Area Dimensions (Length and Width): The larger the area, the more material you’ll need. Doubling the length or width doubles the required volume.
- Depth of Layer: The deeper the layer, the more material is required. A 6-inch layer needs twice as much as a 3-inch layer for the same area.
- Compaction: Crush and run compacts significantly. The calculator implicitly accounts for this through the density value, but actual compaction on-site can vary. More compaction might mean you need slightly more material than calculated if the initial depth wasn’t fully compacted.
- Material Density: Different quarries produce crush and run with slightly different densities depending on the rock type. A higher density means more weight for the same volume. Always ask your supplier for the density if possible.
- Wastage Percentage: Uneven sub-grade, spills during placement, and extra compaction can lead to needing more material. Accurately estimating wastage is crucial to avoid under-ordering.
- Sub-grade Condition: A very soft or uneven sub-grade might require a slightly thicker base or more wastage to achieve the desired final level and stability. You might need more than just a base material calculator if the ground is very poor.
- Moisture Content: The moisture content of the crush and run when delivered and compacted can slightly affect its density and compaction ability.
Frequently Asked Questions (FAQ)
- How much does crush and run weigh?
- Compacted crush and run typically weighs between 110 to 130 pounds per cubic foot, which is about 1.5 to 1.75 tons per cubic yard. Our crush and run calculator uses a default of 120 lbs/ft³.
- How deep should crush and run be for a driveway?
- For a standard residential driveway, a depth of 4 to 6 inches of compacted crush and run is usually sufficient. For areas with heavy vehicles or poor soil, 8-12 inches might be necessary.
- What is the difference between crush and run and #57 stone?
- Crush and run is a mix of various sizes of angular stone and fines (stone dust), allowing it to compact very tightly. #57 stone is a “clean” stone, meaning it’s washed and contains mostly stones of a similar size (around 3/4 to 1 inch) with very few fines, making it good for drainage but not as stable as a base on its own compared to crush and run.
- Can I use the crush and run calculator for other materials?
- Yes, if you know the density of the other material (e.g., topsoil, sand, other gravels), you can input that density to estimate the volume and weight.
- How much does crush and run cost?
- The cost varies by location and supplier, but it’s often sold by the ton or cubic yard. Contact local quarries or landscape suppliers for pricing. You might also need a delivery cost calculator.
- Do I need to compact crush and run?
- Yes, absolutely. Compaction is key to its function as a stable base. It should be compacted in layers (e.g., 2-3 inches at a time) using a plate compactor or roller.
- What is a good wastage percentage to use?
- For most projects, 5% to 10% wastage is a reasonable estimate. If your sub-grade is very uneven, you might consider a slightly higher percentage.
- How many cubic feet are in a ton of crush and run?
- If the density is 120 lbs/ft³, then one ton (2000 lbs) is 2000/120 = 16.67 cubic feet. This varies with density.
Related Tools and Internal Resources
- Gravel Calculator: A more general calculator for various types of gravel and their applications.
- Driveway Gravel Calculator: Specifically tailored for estimating gravel for driveways, considering different layers.
- Base Material Calculator: Useful for calculating the base material needed under pavers or concrete.
- Aggregate Calculator: For various types of construction aggregates.
- Paver Base Calculator: Calculate the amount of base material needed for paver projects.
- Soil Calculator: If you are working with topsoil or garden soil as well.