Visualizing how changes in depth affect the total cubic yards of dirt needed.
Dirt Pricing Estimates (per Cubic Yard)
Material Type
Estimated Cost Range (per cu yd)
Typical Use
Topsoil (Screened)
$25 – $55
Gardening, lawn repair, general landscaping
Compost
$30 – $60
Soil amendment, garden beds
Mulch (Wood Chips)
$20 – $45
Garden beds, tree bases, moisture retention
Gravel (Decorative)
$35 – $70
Pathways, decorative areas, drainage
Fill Dirt
$15 – $30
Leveling ground, filling holes
Note: Prices are estimates and vary significantly by location, supplier, and quality. Delivery fees may apply.
What is Calculating Cubic Yards of Dirt?
Calculating cubic yards of dirt is the process of determining the total volume of soil, sand, gravel, or other bulk materials needed for a project, expressed in cubic yards. This is a fundamental step for anyone undertaking landscaping, construction, gardening, or any project involving the movement or placement of earth. Understanding how to accurately calculate this volume ensures you order the correct amount of material, preventing costly over-ordering or inconvenient under-ordering.
Who should use it? Homeowners planning a garden bed, landscapers preparing a site, contractors needing fill dirt, DIY enthusiasts building retaining walls, or anyone needing to estimate bulk material quantities will benefit from this calculation. It's crucial for budgeting and project planning.
Common misconceptions include assuming all dirt is the same density (it's not), not accounting for compaction (material settles), and simply multiplying length and width without considering depth. Many also forget the conversion from cubic feet to cubic yards.
Dirt Volume Formula and Mathematical Explanation
The core formula to calculate cubic yards of dirt is straightforward, involving the conversion of measurements into a standard volume unit. Here's the step-by-step breakdown:
Calculate the Area: Multiply the length by the width of the space you need to fill.
Convert Depth to Feet: Since the depth is usually measured in inches, divide the depth in inches by 12 to get the depth in feet.
Calculate Volume in Cubic Feet: Multiply the area (in square feet) by the depth (in feet).
Convert Cubic Feet to Cubic Yards: Divide the total volume in cubic feet by 27 (since there are 27 cubic feet in 1 cubic yard).
The longest horizontal dimension of the area to be filled.
Feet (ft)
1 – 100+
Width
The shorter horizontal dimension of the area to be filled.
Feet (ft)
1 – 100+
Depth
The vertical thickness of the material to be applied.
Inches (in)
1 – 24+
Volume (cu ft)
The total space occupied by the material in cubic feet.
Cubic Feet (cu ft)
Calculated
Cubic Yards
The final measurement of the material volume.
Cubic Yards (cu yd)
Calculated
Practical Examples (Real-World Use Cases)
Let's illustrate how to calculate cubic yards of dirt with practical scenarios:
Example 1: Creating a New Garden Bed
You want to create a raised garden bed that is 12 feet long, 6 feet wide, and you want the soil depth to be 8 inches.
Length = 12 ft
Width = 6 ft
Depth = 8 in
Calculation:
Area = 12 ft × 6 ft = 72 sq ft
Depth in feet = 8 in / 12 = 0.67 ft
Volume (cu ft) = 72 sq ft × 0.67 ft = 48.24 cu ft
Cubic Yards = 48.24 cu ft / 27 = 1.79 cu yd
Interpretation: You will need approximately 1.8 cubic yards of soil for your garden bed. It's often wise to round up slightly (e.g., to 2 cubic yards) to account for settling and ensure you have enough.
Example 2: Filling a Small Hole for Landscaping
You need to fill a hole in your yard that measures 5 feet long, 4 feet wide, and the required depth to level it is 1.5 feet (which is 18 inches).
Length = 5 ft
Width = 4 ft
Depth = 18 in
Calculation:
Area = 5 ft × 4 ft = 20 sq ft
Depth in feet = 18 in / 12 = 1.5 ft
Volume (cu ft) = 20 sq ft × 1.5 ft = 30 cu ft
Cubic Yards = 30 cu ft / 27 = 1.11 cu yd
Interpretation: You need about 1.1 cubic yards of fill dirt. Ordering 1.25 or 1.5 cubic yards would be a safe bet to ensure the hole is completely filled and leveled.
How to Use This Dirt Volume Calculator
Our calculator simplifies the process of determining how do I calculate cubic yards of dirt. Follow these simple steps:
Measure Your Area: Accurately measure the length and width of the space you need to cover in feet.
Measure Desired Depth: Determine the depth of the material you need. Measure this in inches.
Enter Values: Input the measured length, width, and depth into the corresponding fields in the calculator.
Click Calculate: Press the "Calculate" button.
How to read results: The calculator will display the primary result in cubic yards. It also shows intermediate values like total volume in cubic feet, depth in feet, and the area in square feet, which can be helpful for understanding the calculation.
Decision-making guidance: Use the calculated cubic yards to get quotes from material suppliers. Always consider adding a small buffer (5-10%) to your order to account for compaction, uneven ground, or slight measurement inaccuracies. The pricing table can help you estimate costs.
Key Factors That Affect Dirt Volume Results
While the basic calculation is straightforward, several factors can influence the actual amount of material you need:
Compaction: Most bulk materials, especially soil and fill dirt, will settle or compact over time, especially when weight is applied or after rain. This means you might need slightly more than your initial calculation suggests.
Material Density: Different types of soil, gravel, and mulch have varying densities. While our calculator focuses on volume, density affects weight, which is sometimes relevant for delivery or structural considerations.
Measurement Accuracy: Precise measurements are key. Inaccurate length, width, or depth readings will lead to incorrect volume calculations. Double-check your measurements.
Ground Contours: If the area isn't perfectly flat, you might need more material to achieve a uniform depth across the entire space. The calculator assumes a level surface.
Waste and Spillage: During transport and spreading, some material can be lost due to spillage or simply not being perfectly contained.
Supplier Tolerances: Bulk material suppliers may have slight variations in the exact volume they deliver. Ordering slightly more helps mitigate this.
Settling Over Time: Natural settling can occur even without added weight, especially with organic materials.
Desired Final Grade: Ensure your depth measurement reflects the final desired level, considering any existing grade or planned slopes.
Frequently Asked Questions (FAQ)
What's the difference between cubic feet and cubic yards?
A cubic yard is a larger unit of volume than a cubic foot. There are exactly 27 cubic feet in 1 cubic yard (3 ft x 3 ft x 3 ft = 27 cu ft). Our calculator handles this conversion for you.
Do I need to add extra for compaction?
Yes, it's generally recommended to add about 5-10% extra material to account for compaction, especially for fill dirt and soil. Our calculator provides the exact volume, so you'll need to add the buffer yourself when ordering.
Can I use this calculator for gravel or mulch?
Yes, the principle of calculating volume remains the same for gravel, mulch, sand, and other similar bulk materials. Just ensure your measurements are accurate for the specific material.
My area is irregular. How do I calculate the volume?
For irregular shapes, break the area down into smaller, regular shapes (rectangles, triangles), calculate the volume for each, and then sum them up. Alternatively, estimate an average length and width. For complex shapes, professional measurement might be best.
What if my depth is more than 12 inches?
The calculator handles depths greater than 12 inches correctly. It converts the inches you enter into feet before calculating the final cubic yards. For example, 18 inches becomes 1.5 feet.
How accurate are the price estimates in the table?
The prices are general estimates and can vary significantly based on your geographic location, the specific supplier, the quality of the material, and whether delivery fees are included. Always get local quotes.
Should I measure my area before or after excavation?
Measure the dimensions of the space you intend to *fill* or *cover* with the new material. If you are excavating, measure the dimensions of the area you need to fill to the desired final grade.
What is the typical depth for a garden bed?
For most vegetable gardens and flower beds, a depth of 6 to 12 inches is common. For deep-rooted plants, you might consider a greater depth.