Dirt Yardage Calculator
Whether you're planning a new garden bed, leveling a yard, or preparing for a construction project, accurately calculating the amount of dirt you need is crucial. Ordering too little means delays and extra delivery fees, while ordering too much leads to wasted money and the hassle of disposal. This guide, along with our handy calculator, will help you determine exactly how many cubic yards of soil, mulch, or gravel your project requires.
Understanding the Basics: The Cubic Yard
Dirt, soil, and other landscaping materials are typically sold by the cubic yard. A cubic yard is a volume measurement representing a cube that is one yard (or three feet) on each side. Therefore, one cubic yard contains 27 cubic feet (3 feet x 3 feet x 3 feet).
The Basic Formula for Rectangular Areas
For any rectangular or square area, the calculation is straightforward:
Volume = Length × Width × Depth
The most important step is to ensure all your measurements are in the same unit, preferably feet, before you multiply. Then, you'll convert the total cubic feet into cubic yards.
Step-by-Step Calculation Guide
Follow these steps to accurately determine your dirt needs:
- Measure the Length: Use a tape measure to find the length of the area you need to fill. Measure from end to end.
- Measure the Width: Measure the width of the area. For irregular shapes, measure at the widest point or break the area into smaller, more manageable sections.
- Measure the Depth: Determine how deep you need the material to be. This could be 4 inches for a thin layer of mulch, 6 inches for a garden bed, or several feet for a significant fill.
- Convert All Measurements to Feet: This is a critical step to avoid errors.
- If you measured in feet, no conversion is needed.
- If you measured in inches, divide by 12 (e.g., 6 inches = 0.5 feet).
- If you measured in yards, multiply by 3 (e.g., 2 yards = 6 feet).
- Calculate the Volume in Cubic Feet: Multiply your converted Length (in feet) by Width (in feet) by Depth (in feet).
- Convert Cubic Feet to Cubic Yards: Divide the total cubic feet by 27 (since there are 27 cubic feet in one cubic yard).
Dealing with Irregular Shapes
Not all projects are perfectly rectangular. For irregular areas, you have a few options:
- Divide and Conquer: Break the complex shape into several simpler shapes (rectangles, squares, triangles, circles). Calculate the volume for each section and then add them together.
- Average Measurement: For slightly irregular areas, you can take several length and width measurements and average them out to get a general estimate. This is less precise but can work for less critical projects.
Important Considerations for Your Dirt Order
While the formula gives you a baseline, a few factors can influence the actual amount of dirt you should order:
Compaction and Settling
New dirt will settle over time, especially after watering or heavy rain. Depending on the type of soil and its intended use, you might want to order an additional 10-20% to account for compaction. If you're using it for a base layer that will be heavily trafficked or built upon, a higher percentage might be needed.
Waste Factor
It's always a good idea to add a small buffer for waste. Spillage, unevenness in your area, or slight miscalculations can mean you come up just short. Adding an extra 5-10% can save you the headache and cost of a second, smaller delivery.
Type of Material
The calculation applies to any bulk material sold by volume, including topsoil, fill dirt, gravel, sand, or mulch. Just ensure you specify the correct material when placing your order.
Example Calculation
Let's say you want to create a garden bed that is 10 feet long, 4 feet wide, and 6 inches deep.
- Length: 10 feet
- Width: 4 feet
- Depth: 6 inches = 0.5 feet (6 / 12)
- Cubic Feet = 10 ft × 4 ft × 0.5 ft = 20 cubic feet
- Cubic Yards = 20 cubic feet / 27 = 0.74 cubic yards
Considering compaction and waste, you might round up to 1 cubic yard to be safe.
Using Our Handy Calculator
To make things even easier, use the "Dirt Yardage Calculator" provided at the top of this page. Simply input your length, width, and depth measurements, choose your units (feet or inches), and click "Calculate Yards" to get an instant estimate. Remember to consider the compaction and waste factors mentioned above when finalizing your order.
Conclusion
Calculating the correct amount of dirt is a fundamental step for any outdoor project. By understanding the simple formula and accounting for practical considerations like compaction and waste, you can ensure your project runs smoothly, stays within budget, and achieves the desired results. Happy digging!