Decomposed Granite Calculator

Enter the size of the path or patio and its compacted depth and get the loose decomposed granite to order in cubic yards, with the compaction allowance added and shown.

A ready-made setup of the Gravel Calculator.

Estimates for planning, not professional advice. Read the full notice.

Path size

Feet and inches, like 12' 6"

Feet and inches, like 12' 6"

Inches, like 4 in

Ask your supplier for the weight per cubic yard. Check your label or supplier.

Example: a decomposed granite path

2.5 yd³ to order (2.31 yd³ exact)

  • Volume in place 50 ft³
  • Cubic yards to order 2.31 yd³
  • Cubic yards at the supplier's step 2.5 yd³

Shopping list

Example: a decomposed granite path
ItemSizeBuy
Decomposed granite by the cubic yard1 yd³2.5 yd³

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    Worked example: a decomposed granite path

    Show the working
    1. Area 20 ft × 10 ft = 200 ft²
    2. Volume at the depth 200 ft² × 3 in = 50 ft³
    3. Add the compaction allowance to get loose material 50 ft³ + 25 % allowance = 62.5 ft³
    4. Add the waste allowance, once 62.5 ft³ + 0 % waste = 62.5 ft³
    5. Cubic yards: divide by the cubic feet in a yard 62.5 ft³ ÷ 27 ft³ in a yd³ = 2.31 yd³
    6. Round up once, to the supplier's yard step 2.31 yd³ = 2.5 yd³

    Assumptions

    The figures behind the example. Sourced figures link to their source below; a default is a starting value to check against your label or supplier.

    Decomposed granite compaction allowance 25%[1]
    Default Kafka Granite's stabilized pathway specification says to allow approximately 25 percent of material depth.
    Landscape waste or overage 0%
    Default No silent overage. Check your label or supplier.
    Supplier's smallest yard step 0.5 yd³
    Default Suppliers sell bulk in steps. Check your label or supplier.
    Supplier's smallest ton step 1 ton
    Default Suppliers sell by the ton in steps. Check your label or supplier.
    Decomposed granite depth, Kafka Granite 3 in[2]
    Kafka Granite's installation guidance for its own pathway mixes: 3 in (pedestrian) or 4 in (vehicular) compacted surface over a 4 to 6 in or 8 to 12 in compacted road base.

    Decomposed granite: compacted depth against loose yards

    Cubic yards of decomposed granite in place, loose with the allowance, and at the supplier's step, for three path sizes at two compacted depths

    Path and compacted depthCubic yards in placeCubic yards looseCubic yards at the supplier's step
    3 ft × 30 ft, 3 in compacted 0.83 yd³1.04 yd³1.5 yd³
    3 ft × 30 ft, 4 in compacted 1.11 yd³1.39 yd³1.5 yd³
    4 ft × 50 ft, 3 in compacted 1.85 yd³2.31 yd³2.5 yd³
    4 ft × 50 ft, 4 in compacted 2.47 yd³3.09 yd³3.5 yd³
    10 ft × 20 ft, 3 in compacted 1.85 yd³2.31 yd³2.5 yd³
    10 ft × 20 ft, 4 in compacted 2.47 yd³3.09 yd³3.5 yd³

    Loose material is the compacted volume plus the allowance in the assumptions, which is the one maker's figure for its own product. Each row is worked out on its own. Product names are trademarks of their owners. HoneyDoMath is not affiliated with, sponsored by or endorsed by Kafka Granite or any other maker.

    Questions

    How many inches of decomposed granite do I need for a path?

    Kafka Granite gives compacted depths for its own pathway mixes, shown in the assumptions with its source. The calculator uses the compacted depth you type and adds the allowance to get the loose amount.

    Why is the amount loose larger than the path volume?

    Material arrives loose and settles when compacted, so the order is the compacted volume plus an allowance. The table shows both volumes side by side.

    Sources (2)
    1. Stabilized Pathway Specification, Section 32 15 40, Kafka Granite LLC, uploaded April 2023. Manufacturer data
      “c. Allow for approximately 25% of material depth for compaction.”
      Per Kafka Granite's specification, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used
    2. Pathway Materials catalog, Basic Installation Information, Kafka Granite LLC, uploaded April 2023; PDF p. 21 (the page headed Basic Installation Information); inch marks read from the PDF text (HC1, November 12, 2026). Manufacturer data
      “Compacted Standard/Stabilized Pathway Mix: 3" (Pedestrian Traffic) or 4" (Vehicular Traffic) ... Compacted Local DOT Road Base Material: 4 – 6" (Pedestrian Traffic) 8 – 12" (Vehicular Traffic)”
      Per Kafka Granite's catalog, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used

    These are summaries of what the sources say, not professional advice. Codes and product data change. Check with your building department and the product label about your own project.

    Sources

    • [1] Kafka Granite, Stabilized Pathway Specification, Section 32 15 40. Checked November 12, 2026. https://www.kafkagranite.com/wp-content/uploads/2023/04/Kafka-Granite-Stabilized-Pathway-Spec.pdf
    • [2] Kafka Granite, Pathway Materials catalog, Basic Installation Information. Checked November 12, 2026. https://www.kafkagranite.com/wp-content/uploads/2023/04/KG-Pathway-Catalog.pdf

    Made with HoneyDoMath.com. Estimates for planning; check product labels and local codes before you buy or build.