How to Calculate Yardage: Estimating Soil, Mulch, and Gravel
Learn how to calculate yardage for landscaping and construction projects. Convert length, width, and depth into cubic yards with formulas and visual examples.
When planning a landscaping or construction project, estimating materials is one of the most critical steps. Whether you are ordering topsoil for garden beds, mulch for flower beds, or gravel for a new driveway, suppliers sell these bulk materials by the cubic yard. Calculating the correct volume ensures you do not overspend or run short mid-project. This guide explains how to calculate yardage using exact formulas, matching the mathematical engine behind our Cubic Yard Calculator.
What is a "Yard"? In the construction and landscaping industry, a yard is shorthand for a cubic yard. This is a measurement of volume, not length. One cubic yard is a cube that is 3 feet long, 3 feet wide, and 3 feet deep.
The Standard Yardage Formula
To calculate the yardage of a rectangular space, you need three measurements: length, width, and depth. The length and width are usually measured in feet, but depth is usually measured in inches. To run the math correctly, you must convert the depth to feet first. Here is the step-by-step formula:
Step 1: Convert Depth to Feet
Divide the depth in inches by 12 to find the depth in feet:
Step 2: Calculate Cubic Feet
Multiply the length, width, and converted depth in feet together to find the volume in cubic feet:
Step 3: Convert to Cubic Yards
Since one cubic yard contains exactly 27 cubic feet, divide your total cubic feet by 27 to find the final yardage:
Visualizing Cubic Yards
As shown in the diagram above, a cubic yard contains 27 individual cubic feet. A single cubic foot is about the size of a standard shipping box, while a cubic yard is roughly the size of a standard washing machine. Understanding this scale helps you check if your calculations make physical sense before placing an order.
Worked Example: Garden Bed Mulching
Assume you are planning to add a layer of mulch to a large garden bed that measures 15 feet wide by 30 feet long. You want the mulch layer to be 3 inches deep. Here is the calculation:
- Convert Depth: 3 inches / 12 = 0.25 feet.
- Calculate Volume in Cubic Feet: 30 ft (length) x 15 ft (width) x 0.25 ft (depth) = 112.5 cubic feet.
- Calculate Cubic Yards: 112.5 / 27 = 4.17 cubic yards.
- With a 10% Waste Factor: 4.17 x 1.1 = 4.59 cubic yards. You should order 4.75 or 5 cubic yards.
Yardage for Different Materials
The calculation for volume is always the same, but the weight of one cubic yard varies dramatically based on the material you are ordering. This chart outlines the average weights and common uses of popular bulk materials:
| Material | Average Weight per Yard | Common Depth | Calculators |
|---|---|---|---|
| Bark Mulch | 600 to 800 lbs (0.3 to 0.4 tons) | 2 to 3 inches | Mulch Calculator |
| Topsoil | 2,200 to 2,400 lbs (1.1 to 1.2 tons) | 4 to 6 inches | Topsoil Calculator |
| Fill Dirt | 2,000 to 2,200 lbs (1.0 to 1.1 tons) | Varies (deep fill) | Fill Dirt Calculator |
| Gravel / Crushed Stone | 2,600 to 2,800 lbs (1.3 to 1.4 tons) | 3 to 4 inches | Gravel Calculator |
Bags or Bulk Delivery?
If you are deciding whether to buy bags from a home improvement store or order a bulk truck delivery, check the volume. Bags of soil or mulch are labeled in cubic feet:
- A standard large bag yields 2 cubic feet. You need 13.5 bags to equal 1 cubic yard.
- A smaller bag yields 1 cubic foot. You need 27 bags to equal 1 cubic yard.
For the garden bed example above (112.5 cubic feet needed), you would need 57 bags of the 2-cubic-foot size. In most areas, any project requiring more than 2 cubic yards is significantly cheaper and easier when ordered as a bulk delivery.
Estimating Dump Truck Loads
A standard single-axle dump truck can carry about 5 to 7 cubic yards of heavy material (like soil or gravel) or up to 10 cubic yards of light material (like mulch). Large commercial dump trucks can hold 12 to 15 cubic yards. Knowing these capacities helps you plan driveway access and unloading space before the delivery arrives.
Let the Calculator do the Work
Our online estimators run this math instantly for rectangular, circular, or irregular spaces. You can switch between different depth units and estimate materials and costs: for mulch, check the Mulch Calculator; for yard renovations, check the Topsoil Calculator; and for structural bases, check the Gravel Calculator.