Dirt Volume Calculator
Use this calculator to determine how many cubic yards of dirt you need for your project. Simply enter the length, width, and desired depth of the area you wish to fill.
Results:
Enter your dimensions above and click "Calculate Dirt Needed" to see the results.
Understanding a "Yard of Dirt"
When you hear someone refer to a "yard of dirt," they are almost always talking about a cubic yard. This is a standard unit of volume used in landscaping, construction, and gardening to measure bulk materials like soil, mulch, gravel, and sand. A cubic yard is a cube that measures 3 feet in length, 3 feet in width, and 3 feet in height. Therefore, one cubic yard contains 27 cubic feet (3 ft x 3 ft x 3 ft = 27 cubic feet).
Why Calculate Dirt Volume?
Accurately calculating the amount of dirt you need is crucial for several reasons:
- Budgeting: Dirt can be expensive, especially when ordering large quantities. Knowing the exact amount helps you avoid over-ordering and wasting money.
- Efficiency: Ordering too little means delays as you wait for a second delivery, while ordering too much leaves you with excess material to dispose of.
- Project Success: Having the right amount ensures your project, whether it's building a raised garden bed, leveling a yard, or filling a trench, can be completed without interruption.
- Logistics: Understanding the volume helps you plan for delivery, storage, and the labor required to move the dirt.
How to Measure Your Area
To calculate the volume of dirt needed, you'll need three basic measurements: length, width, and depth. All measurements should ideally be in feet for easy conversion to cubic yards.
- Length: Measure the longest side of the area you want to fill.
- Width: Measure the shorter side, perpendicular to your length measurement.
- Depth: Determine how deep you want the dirt to be. This is often the trickiest measurement. For example, if you're filling a raised garden bed that is 18 inches high, your depth would be 1.5 feet (18 inches / 12 inches/foot). If you're leveling an uneven area, you might need to estimate an average depth.
For irregular shapes, try to break the area down into smaller, more manageable rectangles or squares, calculate the volume for each, and then add them together.
The Formula for Dirt Calculation
The calculation is straightforward:
- Calculate Cubic Feet: Multiply the length by the width by the depth.
- Convert to Cubic Yards: Divide the total cubic feet by 27 (since there are 27 cubic feet in 1 cubic yard).
Length (feet) × Width (feet) × Depth (feet) = Cubic Feet
Cubic Feet / 27 = Cubic Yards
Using the Dirt Calculator
Our calculator above simplifies this process. Just input your measurements in feet for length, width, and desired depth, and it will instantly provide you with the total volume in both cubic feet and cubic yards. This saves you time and reduces the chance of manual calculation errors.
Important Considerations When Ordering Dirt
- Compaction: Dirt will settle and compact over time, especially after watering or heavy use. It's generally recommended to order 10-20% more dirt than your initial calculation to account for this compaction. For example, if you calculate 5 cubic yards, consider ordering 5.5 to 6 cubic yards.
- Waste and Spillage: A small amount of dirt can be lost due to spillage during delivery or while moving it around your site.
- Irregularities: If your area isn't perfectly rectangular or has varying depths, your initial measurements might be an approximation. It's often safer to round up your final cubic yardage.
- Minimum Orders: Many suppliers have minimum delivery requirements, often one or two cubic yards.
- Type of Dirt: The type of dirt (topsoil, fill dirt, garden mix) can affect its density and how much it compacts.
Example Calculation
Let's say you want to fill a new garden bed that is 15 feet long, 4 feet wide, and you want the soil to be 1.5 feet deep.
- Length: 15 feet
- Width: 4 feet
- Depth: 1.5 feet
Step 1: Calculate Cubic Feet
15 feet × 4 feet × 1.5 feet = 90 cubic feet
Step 2: Convert to Cubic Yards
90 cubic feet / 27 = 3.33 cubic yards
So, you would need approximately 3.33 cubic yards of dirt. Considering compaction, you might round up to 3.5 or even 4 cubic yards to be safe.
Frequently Asked Questions
What if my measurements are in inches?
If your measurements are in inches, divide them by 12 to convert them to feet before using the calculator or formula. For example, 6 inches becomes 0.5 feet (6/12).
How much does a cubic yard of dirt weigh?
The weight of a cubic yard of dirt varies significantly depending on the type of soil, its moisture content, and compaction. On average, a cubic yard of dry topsoil can weigh between 2,000 to 2,400 pounds (1 to 1.2 tons). Wet soil will be heavier.
Can I calculate for a circular area?
Yes, for a circular area, you'll need the radius (half the diameter) and the depth. The formula for cubic feet would be: π × radius (feet)² × depth (feet). Then divide by 27 for cubic yards. Our calculator is designed for rectangular areas, so you'd need to do this calculation manually or use a specialized circular volume calculator.
Is it better to over-order or under-order dirt?
Generally, it's better to slightly over-order (by 10-20%) to account for compaction, settling, and minor miscalculations. Having a little extra is usually less problematic and costly than running out mid-project and needing a second delivery.