A single yard of dirt, which is actually a cubic yard and measures 3 feet by 3 feet by 3 feet, covering a total volume of 27 cubic feet, can cover different amounts of square footage depending on how deep you spread it. If you spread that cubic yard of dirt just 1 inch thick, it can cover about 324 square feet. If you spread it 2 inches thick, it covers about 162 square feet. At 3 inches deep, it covers roughly 108 square feet, and at 4 inches deep, it covers about 81 square feet. The exact area covered, or the square feet per yard of dirt, comes down to the thickness you need for your project. This means figuring out how much area does a yard of soil cover requires knowing your desired depth.
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What a “Yard” of Dirt Really Means
When you hear someone talk about buying a “yard” of dirt, they aren’t talking about the kind of yard around your house. In the world of landscaping and construction, a “yard” is short for a cubic yard. Think of a cube that is 3 feet wide, 3 feet long, and 3 feet high. The space inside that cube is one cubic yard.
Now, let’s break down what that means in terms of volume:
- A cubic yard is 3 feet * 3 feet * 3 feet = 27 cubic feet.
All the calculations for cubic yard soil coverage start with this basic volume: 27 cubic feet. Whether you’re buying topsoil, mulch, or gravel, when sold by the “yard,” it’s usually a cubic yard.
Knowing this 27 cubic feet number is key. It’s the fixed amount of material you have. The area it covers on the ground changes based only on how thick you spread it out.
Why Depth is the Big Deal
Imagine you have a big pile of dirt that makes up one cubic yard. Now, think about spreading that dirt out flat on the ground.
- If you spread it very, very thin (like just half an inch), it will cover a really large area.
- If you spread it very thick (like a foot deep), it will cover a much smaller area.
This is why the depth, or thickness, you need for your project is so important. It’s the direct link between the volume of dirt you have (the cubic yard) and the area it covers on the ground (in square feet). The thinner the layer, the more square feet per yard of dirt you get.
Deciphering the Calculations
So, how do we go from 27 cubic feet (the volume of one cubic yard) to square feet (the area it covers)? We use the depth.
The basic idea is:
Volume = Area * Depth
If we rearrange this formula to find the area, it becomes:
Area = Volume / Depth
We know the volume is 27 cubic feet. But wait, the depth is usually measured in inches for landscaping projects (like 2 inches deep for a garden bed). Our volume is in feet, so we need to make the units match.
We need to convert the depth from inches into feet.
There are 12 inches in 1 foot.
So, if your depth is, say, 3 inches, you convert it to feet like this:
Depth in feet = Depth in inches / 12
Depth in feet = 3 inches / 12 = 0.25 feet
Now we can use our formula:
Area (in square feet) = 27 cubic feet / Depth (in feet)
Let’s do the calculation for a 3-inch depth:
Area = 27 cubic feet / 0.25 feet
Area = 108 square feet
So, one cubic yard of dirt spread 3 inches deep covers 108 square feet. This shows the cubic yards to square feet conversion for soil relies completely on that depth measurement.
Square Feet Covered by Depth
To make things easy, here is a table showing how much area one cubic yard of dirt covers at common depths used in landscaping and gardening. This helps you see the soil coverage depth yard clearly.
| Desired Depth (Inches) | Desired Depth (Feet) | Calculation (27 cu ft / Depth in feet) | Approximate Area Covered (Square Feet) |
|---|---|---|---|
| 1 inch | 1/12 or ≈ 0.0833 ft | 27 / (1/12) = 27 * 12 | 324 sq ft |
| 2 inches | 2/12 or ≈ 0.1667 ft | 27 / (2/12) = 27 * 6 | 162 sq ft |
| 3 inches | 3/12 or 0.25 ft | 27 / 0.25 | 108 sq ft |
| 4 inches | 4/12 or ≈ 0.3333 ft | 27 / (4/12) = 27 * 3 | 81 sq ft |
| 5 inches | 5/12 or ≈ 0.4167 ft | 27 / (5/12) | 64.8 sq ft |
| 6 inches | 6/12 or 0.5 ft | 27 / 0.5 | 54 sq ft |
| 7 inches | 7/12 or ≈ 0.5833 ft | 27 / (7/12) | ≈ 46.3 sq ft |
| 8 inches | 8/12 or ≈ 0.6667 ft | 27 / (8/12) = 27 * 1.5 | 40.5 sq ft |
| 9 inches | 9/12 or 0.75 ft | 27 / 0.75 | 36 sq ft |
| 10 inches | 10/12 or ≈ 0.8333 ft | 27 / (10/12) | 32.4 sq ft |
| 11 inches | 11/12 or ≈ 0.9167 ft | 27 / (11/12) | ≈ 29.5 sq ft |
| 12 inches (1 foot) | 1 ft | 27 / 1 | 27 sq ft |
This table clearly shows the inverse relationship: as the depth goes up, the area covered goes down. The value for 1 inch depth, 324 sq ft, is especially useful because it gives you the cubic yard coverage per inch. If you need a depth that’s not on this table, you can easily figure it out by dividing 324 by your desired depth in inches. For example, for 1.5 inches deep, you would do 324 / 1.5 = 216 sq ft.
Things That Can Change Coverage a Little
While the math based on volume and depth gives us the main answer, a few real-world things can slightly affect the final coverage you get from a delivered yard of topsoil coverage or other material.
- Compaction: When dirt is delivered, it’s usually loose. When you spread it and walk on it or water it, it settles and becomes more compact. This means you might need a little extra to reach your target settled depth. Suppliers usually sell by loose cubic yard volume.
- Type of Material: Different materials compact differently. Sand compacts easily. Materials with lots of organic matter might settle more over time as the organic matter breaks down. Fluffy mulch won’t compact as much as heavy, wet soil. While the initial volume in the truck is one cubic yard, how it behaves after spreading varies.
- Waste and Spills: It’s rare to use every single bit of dirt perfectly. Some might get spilled, some might be hard to get out of the truck or wheelbarrow. It’s always a good idea to add a little extra (maybe 5-10%) to your calculation to account for this.
Because of these factors, the coverage numbers in the table are excellent estimates, but treat them as minimums. You might need slightly more material than the calculation suggests, especially if you want a specific settled depth.
Getting Your Area Measurement
Before you can calculate soil needed square feet, you need to know the size of the area you want to cover. Here’s how to measure common shapes:
H4: Measuring Simple Shapes
-
Square or Rectangle: This is the easiest.
- Measure the length of the area in feet.
- Measure the width of the area in feet.
- Multiply length by width: Length (ft) * Width (ft) = Area (sq ft).
- Example: A rectangular garden bed is 10 feet long and 5 feet wide. Area = 10 ft * 5 ft = 50 sq ft.
-
Circle:
- Measure the distance across the center of the circle (this is called the diameter) in feet.
- Divide the diameter by 2 to get the radius (Radius = Diameter / 2).
- Use the formula: Area = π * radius * radius (where π is about 3.14).
- Example: A circular area for a tree is 6 feet across (diameter). The radius is 6 / 2 = 3 feet. Area = 3.14 * 3 ft * 3 ft = 3.14 * 9 = 28.26 sq ft.
H4: Measuring Less Simple Shapes
-
Multiple Rectangles or Squares: If your area is shaped like an ‘L’ or a ‘T’, break it down into simple rectangles or squares.
- Measure each smaller rectangle/square separately.
- Calculate the area of each part.
- Add the areas of all the parts together to get the total area.
-
Odd or Irregular Shapes: This is a bit trickier but doable.
- Try to break the shape down into a few simple shapes (rectangles, squares, circles, or even triangles).
- Measure and calculate the area of each simple shape.
- Add them up. This will give you a good estimate.
- Alternatively, you can lay a grid (like using string or marking paint) over the area and count the squares. Or, use an online mapping tool (like Google Earth) to draw the area and get a measurement.
Always measure twice to be sure! And remember to use feet for your measurements when calculating area in square feet.
Steps to Calculate Soil Needed
Now that you know how much area you need to cover and what depth you want, you can figure out exactly how much dirt to order. This helps you calculate soil needed square feet for your specific project.
Here are the steps:
H4: Step 1: Measure Your Area in Square Feet
Use the methods above to find the total area you want to cover. Let’s say you measured a rectangular area that is 20 feet long and 15 feet wide.
Area = 20 ft * 15 ft = 300 sq ft.
H4: Step 2: Decide on Your Desired Depth
Think about why you need the dirt.
* Putting down a thin layer (1-2 inches) might be for leveling or adding a little topdressing.
* Adding 3-4 inches is common for new garden beds or improving existing soil.
* Adding 6 inches or more might be for raising a bed significantly or major grading.
Let’s say you want to add 4 inches of topsoil to your 300 sq ft area.
Desired Depth = 4 inches.
H4: Step 3: Calculate the Total Volume Needed (in Cubic Feet)
We use the formula from before: Volume = Area * Depth.
But remember, the depth must be in feet.
Depth in feet = Desired Depth in inches / 12
Depth in feet = 4 inches / 12 = 1/3 foot or approximately 0.3333 feet.
Now calculate the volume:
Volume (cubic feet) = Area (sq ft) * Depth (feet)
Volume (cubic feet) = 300 sq ft * (1/3) ft
Volume (cubic feet) = 100 cubic feet.
This is the total amount of dirt you need in cubic feet. This is the key volume to area soil calculation step.
H4: Step 4: Convert Cubic Feet to Cubic Yards
Dirt is usually sold by the cubic yard. We know that 1 cubic yard is 27 cubic feet. To find out how many cubic yards you need, divide your total cubic feet by 27.
Cubic Yards Needed = Total Cubic Feet / 27
Cubic Yards Needed = 100 cubic feet / 27 cubic feet/yard
Cubic Yards Needed ≈ 3.7 cubic yards.
H4: Step 5: Account for Waste and Settle
As mentioned before, it’s wise to order a little extra dirt. Adding 5-10% is common. Let’s add 10% in this example.
Extra amount = Cubic Yards Needed * 10%
Extra amount = 3.7 * 0.10 = 0.37 cubic yards.
Total Cubic Yards to Order = Cubic Yards Needed + Extra amount
Total Cubic Yards to Order = 3.7 + 0.37 = 4.07 cubic yards.
Since you can’t usually order fractions of a cubic yard (you typically order in half-yard or full-yard increments), you would likely round up to the nearest half or full yard. In this case, ordering 4 or 4.5 cubic yards would be smart. Ordering 4 cubic yards would get you very close, while 4.5 would give you a comfortable buffer.
This full process shows you how to calculate soil needed square feet and convert it into the common unit for ordering.
Working Through Another Example
Let’s try another scenario. You want to fill a raised garden bed that is 8 feet by 4 feet and you want the soil to be 10 inches deep.
-
Measure Area:
Area = Length * Width
Area = 8 ft * 4 ft = 32 sq ft. -
Decide Depth:
Desired Depth = 10 inches. -
Calculate Volume (Cubic Feet):
Convert depth to feet: Depth in feet = 10 inches / 12 = 10/12 = 5/6 feet (approximately 0.8333 feet).
Volume (cubic feet) = Area (sq ft) * Depth (feet)
Volume (cubic feet) = 32 sq ft * (5/6) ft
Volume (cubic feet) = 160/6 cubic feet = 80/3 cubic feet ≈ 26.67 cubic feet. -
Convert to Cubic Yards:
Cubic Yards Needed = Total Cubic Feet / 27
Cubic Yards Needed = 26.67 / 27 ≈ 0.988 cubic yards. -
Account for Waste:
Add 10% for safety: 0.988 * 0.10 = 0.0988 cubic yards.
Total Cubic Yards to Order = 0.988 + 0.0988 ≈ 1.087 cubic yards.
In this case, you would likely order 1 cubic yard or possibly 1.5 cubic yards if you want to be extra safe, depending on the supplier’s minimum order and delivery cost structure. Since 0.988 is so close to 1, one yard might be just enough, but having a little extra is often worth it.
Using a Dirt Coverage Calculator
Many websites for landscape suppliers or home improvement stores have a dirt coverage calculator square feet. These tools are very helpful and do the math for you.
How they usually work:
- You enter the shape of your area (rectangle, circle, or sometimes they allow for multiple areas).
- You enter the measurements of your area in feet.
- You enter the desired depth in inches.
- You click “Calculate”.
The calculator then performs the same steps we just did: calculates the area, converts the depth to feet, calculates the total cubic feet needed, and finally divides by 27 to give you the number of cubic yards. Some calculators might even ask about compaction or add a small percentage for waste automatically.
These tools are great for quickly getting an estimate, but it’s always good to understand the math behind them so you can double-check or calculate for irregular areas the tool doesn’t handle. Knowing the relationship between cubic yard soil coverage and depth lets you verify the calculator’s output.
Grasping the Coverage of Different Materials
The calculations we’ve discussed apply to any loose material sold by volume (cubic yard), not just soil. This includes:
- Yard of Topsoil Coverage: This is very common for gardens and lawns.
- Mulch (wood chips, bark, etc.)
- Gravel (various sizes)
- Sand
- Compost
The volume of a cubic yard (27 cubic feet) is the same for all these materials when measured in a truck or pile. Therefore, the cubic yard coverage per inch (324 sq ft per inch depth) and the square feet per yard of dirt (or mulch, or gravel) values based on depth remain the same in theory.
In practice, slight differences might appear due to how the material settles or how easy it is to spread evenly. For example, fluffy mulch might seem like it covers more initially than heavy soil, but once it settles or decomposes, the coverage might change. However, for planning and ordering purposes, you use the same cubic yard to square foot conversion based on depth, regardless of whether it’s dirt, mulch, or gravel.
Ordering and Delivery Pointers
When you order dirt by the cubic yard, it usually comes in a dump truck.
- Minimum Orders: Many suppliers have a minimum delivery amount, often 1 or 2 cubic yards.
- Delivery Fees: There is almost always a delivery fee, which can be a significant part of the cost, especially for small orders or long distances. Sometimes ordering a bit more (like 2 yards instead of 1.1) might be cheaper overall due to the delivery fee structure.
- Delivery Location: Think carefully about where the truck can safely dump the dirt. It needs to be a place where a large, heavy truck can drive and maneuver. Avoid soft ground, septic systems, or blocking access. Have a clear spot ready.
- Timing: Plan the delivery for a time when you are ready to start spreading. A big pile of dirt can be an obstacle and can get very hard to work with if it sits through heavy rain.
Knowing your required cubic yard soil coverage helps you place the right order the first time, avoiding the hassle and cost of a second delivery or having too much material leftover.
Tips for Spreading Dirt Evenly
Getting even soil coverage depth yard across your project area can be challenging but leads to better results.
- Break Down the Pile: Don’t try to spread the entire large pile from one spot. Use a shovel and wheelbarrow to move smaller piles closer to where you need them.
- Use Stakes and String: If you need a very precise depth, set up stakes at your desired soil level and run string between them as a guide.
- Start Thick and Spread Out: It’s easier to spread a slightly thicker layer thinner than to try and add more to thin spots later.
- Use the Right Tools: A shovel is good for moving dirt. A rake is excellent for spreading and leveling. A wheelbarrow is essential for transport. For larger areas, a landscape rake or even a small tractor/skid steer can save a lot of time and effort.
- Check Your Depth: Periodically use a small ruler or tape measure to check that you are reaching your target depth evenly across the area.
Achieving the correct and consistent depth is key to making sure your calculation for how much area does a yard of soil cover translates accurately into your finished project.
FAQ Section
Here are some common questions people ask about dirt coverage.
H4: How much is a yard of dirt in weight?
The weight of a cubic yard of dirt varies a lot depending on the type of dirt and how much moisture is in it. Dry, sandy soil might weigh around 2,000-2,400 pounds (1 ton to 1.2 tons) per cubic yard. Wet, heavy clay soil could weigh 2,800-3,200 pounds (1.4 tons to 1.6 tons) or even more. This is why dirt is usually sold by volume (cubic yards) rather than weight, as volume is consistent while weight changes with moisture.
H4: Is a cubic yard the same as 27 cubic feet?
Yes, exactly. A cubic yard is defined as a cube measuring 3 feet on each side (length, width, height). So, the volume is 3 ft * 3 ft * 3 ft = 27 cubic feet.
H4: How deep should I spread topsoil?
The ideal depth depends entirely on the purpose.
* For overseeding or leveling a lawn: 0.5 to 1 inch.
* For improving existing garden beds: 2 to 4 inches worked into the top layer.
* For establishing new garden beds: 6 to 12 inches or more, depending on the plants you plan to grow.
* For filling low spots or grading: The depth needed varies based on the unevenness.
H4: How much area does a bulk bag of soil cover?
Bulk bags are becoming more popular. They are often sold in various sizes, but a common size is one cubic yard (27 cubic feet), just like loose dirt. If it’s a one-cubic-yard bag, it covers the same area as loose dirt at a given depth (e.g., 108 sq ft at 3 inches deep). Always check the volume listed on the bag or with the supplier.
H4: How can I figure out the cost per square foot?
Once you know how much area a yard covers at your desired depth, you can figure out the cost per square foot.
1. Find the total cost of one cubic yard delivered (material cost + delivery fee divided by number of yards ordered).
2. Find out how many square feet that yard covers at your depth (refer to the table or calculate it).
3. Divide the total cost per yard by the square feet it covers.
* Example: One yard costs $50 delivered. You spread it 4 inches deep, covering 81 sq ft. Cost per sq ft = $50 / 81 sq ft ≈ $0.62 per square foot.
H4: Why is calculating soil needed important?
Calculating accurately helps you avoid two main problems:
1. Not ordering enough: This means delaying your project to wait for another delivery, plus paying a second delivery fee.
2. Ordering too much: You end up with a large pile of extra dirt you have to find a place for, give away, or pay to have hauled away. Getting the estimate right saves time, money, and hassle. Using the correct cubic yards to square feet conversion for soil is key.
Knowing how much area does a yard of soil cover at different depths empowers you to plan your landscaping or gardening projects effectively, order the right amount of material, and get the job done efficiently. Remember, 27 cubic feet is your starting point, and your desired depth is the key to unlock the square feet per yard of dirt.