Last updated: March 2026
How to Estimate Landscape Materials
Landscape material calculations follow the same basic formula regardless of whether you are working with mulch, gravel, river rock, or compost: measure the area, choose a depth, and calculate the volume. The key differences between materials are weight, cost, and recommended depth.
Start by measuring each bed or area individually. Rectangular beds are length times width. Circular beds use pi times radius squared. For irregular shapes, break them into simpler shapes and add the areas together. Our calculator handles rectangles, circles, triangles, and L-shaped beds automatically.
Once you have your total area, multiply by the depth to get volume. The standard depth for organic mulch is 3 inches (0.25 feet). Gravel walkways and patios typically need 2 to 3 inches. Decorative rock beds usually require 2 inches. Divide your cubic feet by 27 to get cubic yards, which is how bulk materials are sold.
Material Comparison Guide
For garden beds: Wood mulch and pine bark are the best all-around choices. They suppress weeds, retain moisture, regulate soil temperature, and improve soil structure as they decompose. Apply 3 inches deep and refresh annually.
For pathways and driveways: Pea gravel and crushed stone provide excellent drainage and a stable walking surface. They require landscape fabric underneath and edging to contain them. Plan for 2 to 3 inches deep over a compacted base.
For decorative areas: River rock and decorative stone create low-maintenance, permanent landscape features. They are the most expensive option upfront but never need replacing. Use landscape fabric underneath and plan for 2 inches of depth.
For soil improvement: Compost adds nutrients and improves soil structure. Apply 2 to 3 inches and work it into the top few inches of soil for garden beds, or use it as a top dressing on lawns at 0.5 to 1 inch deep.
Frequently Asked Questions
How do I calculate landscape materials?
Measure the area of each bed in square feet (length times width for rectangles, pi times radius squared for circles). Multiply by the desired depth in feet (3 inches = 0.25 feet) to get cubic feet. Divide by 27 to convert to cubic yards. One cubic yard covers about 108 square feet at 3 inches deep.
How much gravel do I need for a walkway?
For a gravel walkway, plan for 2 to 3 inches of depth on top of a compacted base. A 3-foot wide, 20-foot long walkway is 60 square feet. At 3 inches deep, you need about 15 cubic feet or 0.56 cubic yards of gravel. Gravel weighs approximately 2,700 pounds per cubic yard, so this walkway would require about 1,500 pounds.
What is the cheapest landscape material?
Wood mulch is generally the cheapest option at $25 to $45 per cubic yard for bulk delivery. Pine bark runs $25 to $40 per cubic yard. Buying in bulk rather than bags saves 30 to 50 percent on material costs. Free mulch is sometimes available from tree trimming services and municipal composting programs.
How much does landscape rock weigh?
Landscape rock is significantly heavier than organic mulches. Pea gravel and crushed stone weigh about 2,700 pounds per cubic yard. River rock weighs about 2,600 pounds per cubic yard. A standard pickup truck can safely haul about one cubic yard (roughly one ton) of rock, so larger projects require multiple trips or professional delivery.
Should I use landscape fabric under mulch?
Landscape fabric is recommended under inorganic materials like gravel and river rock to prevent them from sinking into the soil and to block weeds. For organic mulches like wood chips and bark, fabric is generally not recommended because it prevents the mulch from decomposing into the soil and can create a barrier that reduces soil health over time.