How to Calculate the Amount of Landscaping Rock You Need

Whether you’re creating a stunning rock garden, laying a gravel pathway, or building a dry riverbed, calculating the right amount of landscaping rock is essential. Ordering too little means multiple trips or delivery fees, while over-ordering results in wasted materials and extra cost. This guide will walk you through exactly how to measure and calculate the amount of rock you need for your next project.

Why Accurate Calculation Matters

Accurate rock estimation saves you time, money, and frustration. Bulk landscaping materials are usually sold by the cubic yard, so having a solid understanding of the volume you need will ensure a smoother project with fewer delays.

Step 1: Measure Your Space

To get started, measure the length, width, and depth of the area where you’ll be placing the rock. Always use the same units (feet or inches) for consistency.

Example: If you’re covering a garden bed that’s 10 feet long and 6 feet wide with 2 inches of rock:

• Length = 10 ft
• Width = 6 ft
• Depth = 2 inches (convert to feet: 2 / 12 = 0.167 ft)

Step 2: Use the Volume Formula

To calculate cubic feet:

Length x Width x Depth = Cubic Feet

Using our example:

10 x 6 x 0.167 = 10.02 cubic feet

Step 3: Convert Cubic Feet to Cubic Yards

There are 27 cubic feet in a cubic yard:

Cubic Feet / 27 = Cubic Yards

For our example:

10.02 / 27 = 0.37 cubic yards

Step 4: Round Up

Always round up slightly to account for settling and uneven distribution. In our example, you’d order 0.5 cubic yards to be safe.

Pro Tips for Rock Calculations

• Add extra: Order 5–10% more material than calculated.
• Depth matters: For walkways, use 2-3 inches; for beds, 1-2 inches is sufficient.
• Use a calculator: Many online tools can make this easier—US Rock’s team can also assist with custom estimates.

Common Coverage Rates

• 1 cubic yard covers ~324 sq ft at 1 inch deep
• 1 cubic yard covers ~162 sq ft at 2 inches deep
• 1 cubic yard covers ~108 sq ft at 3 inches deep

Ready to Rock Your Project?

Accurate material calculation is key to a successful landscaping project. Use these simple steps to estimate your rock needs, or contact the experts at US Rock for help. We’re here to provide high-quality landscaping materials and guidance every step of the way.

Visit usrock.com to start planning your perfect outdoor space!