Crusher Run Calculator

Accurately estimate the required amount of crusher run aggregate for your project.

What is Crusher Run?

Crusher run, also known as “Graded Aggregate Base” (GAB), “crush and run,” or “driveway gravel,” is a versatile construction aggregate. It consists of a mixture of coarse crushed stone and fine rock dust (fines). This combination of different particle sizes is key to its functionality. When compacted, the larger stones provide strength and a load-bearing structure, while the fines fill the voids, creating a tight, interlocking, and stable surface. This makes it an ideal material for creating sub-bases for roads, driveways, patios, and building foundations. Using a crusher run calculator is the first step in planning any project requiring a solid, well-draining base layer.

Crusher Run Calculator Formula and Explanation

Calculating the required amount of crusher run involves determining the volume of the area to be filled and then converting that volume into weight based on the material’s density. Our crusher run calculator automates this process for you.

The basic formulas are:

1. Area (ft²) = Length (ft) × Width (ft)
2. Volume (yd³) = (Length (ft) × Width (ft) × Depth (ft)) / 27
3. Total Weight (tons) = Volume (yd³) × Density (tons/yd³)

The calculator also includes a compaction factor, as loose crusher run will settle and reduce in volume when compacted. An additional 5-15% is often required.

Variables Table

Variables used in the crusher run calculation.

Variable	Meaning	Common Unit	Typical Range
Length	The longest dimension of your project area.	Feet / Meters	5 – 100+
Width	The shorter dimension of your project area.	Feet / Meters	3 – 50+
Depth	The thickness of the crusher run layer.	Inches / Centimeters	4 – 8 inches
Density	The weight of the material per unit of volume.	tons/yd³ or tonnes/m³	1.4 – 1.6 tons/yd³

Practical Examples

Example 1: Standard Driveway

You are building a new driveway that is 50 feet long by 12 feet wide and you need a base layer 6 inches deep.

• Inputs: Length = 50 ft, Width = 12 ft, Depth = 6 in
• Calculation:
  • Area = 50 × 12 = 600 ft²
  • Volume = (50 × 12 × 0.5) / 27 = 11.11 yd³
  • Weight (at 1.5 tons/yd³) = 11.11 × 1.5 = 16.67 tons
• Result: You would need approximately 16.67 tons of crusher run before accounting for compaction.

Example 2: Small Patio Base (Metric)

You are creating a base for a small patio that measures 4 meters long by 3 meters wide, with a required depth of 15 centimeters.

• Inputs: Length = 4 m, Width = 3 m, Depth = 15 cm
• Calculation:
  • Area = 4 × 3 = 12 m²
  • Volume = 4 × 3 × 0.15 = 1.8 m³
  • Weight (at 1.8 tonnes/m³) = 1.8 × 1.8 = 3.24 tonnes
• Result: You would need approximately 3.24 tonnes of crusher run. Check out our patio paver calculator to estimate materials for the next step.

How to Use This Crusher Run Calculator

Our tool simplifies project planning. Follow these steps:

1. Select Units: Choose between Imperial (feet/inches) or Metric (meters/cm). The labels will update automatically.
2. Enter Dimensions: Input the length, width, and desired depth of your project area.
3. Adjust Density: The default density is a common average. If your supplier provides a specific density, enter it for a more accurate calculation.
4. Set Compaction: Enter a percentage for compaction. 10% is a safe bet for most projects to ensure you don’t run short.
5. Review Results: The calculator instantly provides the total weight needed (primary result) along with the area and volume.

Key Factors That Affect Crusher Run Calculations

• Moisture Content: Wet crusher run is heavier than dry. The density value helps account for this, but be aware that recent rainfall can affect the weight of your delivery.
• Subgrade Condition: A soft or uneven subgrade may require a deeper layer of crusher run for proper stabilization, increasing the total amount needed.
• Compaction Method: The amount of compaction achieved depends on the equipment used (e.g., hand tamper vs. vibratory plate compactor). Professional equipment achieves higher compaction, requiring slightly more material initially.
• Material Source: The type of rock (e.g., granite, limestone) affects the density. Always ask your supplier for the material’s specific density if possible.
• Intended Use: A base for a simple walkway needs less depth than a heavy-duty driveway intended for RVs or large trucks. Plan your depth accordingly. Our driveway cost calculator can help budget the full project.
• Waste Factor: It’s wise to add a small buffer (around 5%) for spillage and minor measurement inaccuracies.

Frequently Asked Questions (FAQ)

1. How much does 1 yard of crusher run weigh?
Typically, 1 cubic yard of crusher run weighs between 1.4 to 1.6 US tons (2,800 to 3,200 pounds), depending on the rock type and moisture content. Our crusher run calculator uses 1.5 tons as a default.

2. What is the best depth for a crusher run driveway?
For a standard residential driveway, a compacted depth of 4 to 6 inches is recommended. For areas with heavy vehicle traffic, 6 to 8 inches is preferable.

3. Can I use this calculator for other materials like gravel or sand?
Yes, you can. The key is to change the “Material Density” value to match the material you are using. For example, a gravel calculator is essentially the same but with a density specific to pea gravel or another type.

4. What does the compaction factor mean?
Crusher run is delivered loose. When you spread and compact it, the air pockets are removed, and the volume decreases. The compaction factor adds extra material to your order to compensate for this loss in volume, ensuring you have enough for the final compacted depth.

5. Should I use feet and inches or decimal feet?
Our calculator is designed for convenience. If you select the Imperial system, you enter length and width in feet, but the depth in inches, which is how most people measure it. The tool handles the conversion automatically.

6. How do I convert tons to cubic yards?
To convert tons to cubic yards, you divide the weight in tons by the material’s density (in tons per cubic yard). For example, 15 tons / 1.5 tons/yd³ = 10 cubic yards.

7. Why are the fines important in crusher run?
The fine particles (rock dust) are critical. They fill the voids between the larger angular stones, and when compacted, they create a tight, interlocking matrix that resists shifting and provides excellent stability.

8. Is crusher run the same as #57 stone?
No. #57 stone is “clean-washed,” meaning it does not contain the fines that crusher run does. #57 stone is excellent for drainage but does not compact as tightly as crusher run, making it less suitable as a top-layer base.