For a 50 × 3-foot path at a selected 3-inch finished thickness, geometric compacted volume is 1.388889 cu yd. The loose quantity and tonnage still depend on the exact decomposed-granite product and verified compaction/coverage information. Hello Gravel lists a commercial estimate of 70–80 sq ft per ton at 3 inches compacted, giving 1.875–2.142857 tons for 150 sq ft.1 That range is not permission to round the order to two tons regardless of actual coverage.
The geometric formula
Volume (cu yd) = area (sq ft) × selected thickness (in) / 324. Label the thickness as loose or compacted. For a rectangle, area = length × width. Break irregular or changing-thickness areas into separate non-overlapping sections. This formula does not select a suitable layer thickness or certify a walkway/driveway assembly.
Geometric volume by selected thickness
Our table shows selected uniform-thickness scenarios only. If thickness is compacted, the figures are compacted geometry, not the loose order. Base aggregate is separate.
| Area | Selected 2 in | Selected 3 in | Selected 4 in |
|---|---|---|---|
| 100 sq ft | 0.617284 cu yd | 0.925926 cu yd | 1.234568 cu yd |
| 150 sq ft | 0.925926 cu yd | 1.388889 cu yd | 1.851852 cu yd |
| 200 sq ft | 1.234568 cu yd | 1.851852 cu yd | 2.469136 cu yd |
| 500 sq ft | 3.086420 cu yd | 4.629630 cu yd | 6.172840 cu yd |
| 1000 sq ft | 6.172840 cu yd | 9.259259 cu yd | 12.345679 cu yd |
Supplier coverage reference, not a universal density
Hello Gravel states the following approximate coverage at compacted depth and says actual coverage varies by material, soil and compaction.1 Use it only as that supplier’s planning reference. Confirm whether the final quote uses short tons and whether its coverage applies to your exact product/installation.
| Selected compacted depth | Hello Gravel approximate sq ft/ton | For 100 sq ft | For 150 sq ft |
|---|---|---|---|
| 2 in | 100–120 | 0.833333–1.000000 tons | 1.250000–1.500000 tons |
| 3 in | 70–80 | 1.250000–1.428571 tons | 1.875000–2.142857 tons |
| 4 in | 50–60 | 1.666667–2.000000 tons | 2.500000–3.000000 tons |
Tons from applicable coverage = area / sq ft per ton. The lower mass uses the higher coverage. Do not add a loose-volume compaction factor to a mass estimate whose coverage already applies at finished compacted depth; confirm the coverage basis first. If converting loose yards to short tons instead, use the exact product’s matching loose density: short tons = loose cu yd × lb per loose cu yd / 2,000.
“20–25% compaction” is not a defined multiplier
Kafka’s cited Standard Pathway Mix specification says to “allow for 20–25% compaction,” but does not define the percentage’s volume denominator.2 Therefore we do not convert that phrase automatically into ×1.20 or ×1.25. Nor does a 95% Proctor density target mean 5% volume loss: the specification’s density target and a loose-volume conversion are different quantities.
If the supplier defines 25% extra loose volume relative to the finished volume, then loose = finished × 1.25. If it defines 25% volume loss relative to the initial loose volume, finished = loose × 0.75, so loose = finished / 0.75 = finished × 1.333333. Ask which definition and product conversion applies before ordering. These are mathematical interpretations, not a claim about Kafka’s intended factor.
Product and specification scope
Kafka’s document is a project-specification template for its Standard Pathway Mix, with sections the specifier may retain/delete and details coordinated with the project.2 It lists minimum compacted surface thicknesses of 3 inches for pedestrian paths and 4 inches for vehicular drives, with separate subbase requirements. Those are that system’s specification details, not a design for all loose, stabilized or resin-bound DG products.
Do not combine Hello Gravel’s discussion of polymer-stabilized DG with Kafka’s Standard Pathway Mix specification as if they were the same product or assembly. Confirm the actual product, site drainage, traffic, accessibility and local/project requirements. This page estimates quantities; it does not approve a vehicle surface or select a binder.
Three checked examples
1. A 150-sq-ft path and coverage range
At selected 3-inch compacted thickness, geometry = 150 × 3 / 324 = 1.388889 cu yd. Using Hello Gravel’s approximate 70–80 sq-ft/ton reference gives 150 / 80 = 1.875 tons through 150 / 70 = 2.142857 tons.1 Two tons would cover only 140 sq ft at the lower 70-sq-ft/ton figure. Choose the actual verified supplier quantity and sales increment rather than rounding the range’s middle down.
2. Two different meanings of 25%
A selected 10 × 10-foot patio at 3 inches compacted has 100 × 3 / 324 = 0.925926 cu yd. Under a hypothetical 25% addition to finished volume, loose quantity = (100 × 3 / 324) × 1.25 = 1.157407 cu yd. Under a hypothetical 25% loss from loose volume, loose quantity = (100 × 3 / 324) / 0.75 = 1.234568 cu yd. Neither interpretation is assigned to Kafka without clarification.
3. Separate surface and subbase quantities
For a hypothetical project plan selecting a 200-sq-ft area, 4-inch compacted DG surface and 8-inch compacted subbase, surface geometry = 200 × 4 / 324 = 2.469136 cu yd; subbase geometry = 200 × 8 / 324 = 4.938272 cu yd. Suppose verified product conversions are 1.20 loose/compacted for the surface and 1.15 for the subbase: loose quantities become 2.962963 cu yd and 5.679012 cu yd separately. The factors and layer choices are hypothetical; this arithmetic does not establish that the assembly is suitable for vehicles.
Base, edging and other materials
Count the specified base, edging and accessories separately. Kafka’s template describes a subbase and includes optional edging selected by the specifier.2 It does not support the old claim that its example steel edging is mandatory for every DG installation. Use the actual approved detail and perimeter; do not infer a universal base or edging requirement from this quantity table.
Bag conversion
For an exact matching product sold in weight-labeled bags, bags = round up [verified short tons × 2,000 / net lb per bag]. For volume-labeled bags, divide the verified loose-volume target by package cu ft after converting yards × 27. Do not mix a bulk product’s coverage with a different bagged formulation or assume pounds imply a fixed cubic-foot volume.
FAQ
How much does a ton of DG cover?
The cited commercial reference gives approximate 100–120 sq ft at 2 inches, 70–80 at 3 inches and 50–60 at 4 inches compacted.1 Those are scoped estimates. Confirm your exact supplier/product coverage and ton unit.
Do I multiply compacted yards by 1.25?
Only when the applicable supplier/project factor is actually 1.25. The phrase “25% compaction” alone does not establish that definition.
How deep should a DG path be?
Kafka’s cited Standard Pathway Mix template gives a 3-inch compacted pedestrian minimum.2 Use the exact product’s current project instructions and local requirements; this is not a universal specification.
Does DG volume include the base?
No. Calculate the separately specified base material, dimensions and conversion. Do not add compacted DG and base geometry and then apply one shared loose-density factor.
Related guides
Gravel calculator | Gravel volume-to-weight guide | Gravel walkway quantity guide
Sources
- Hello Gravel: Decomposed Granite Calculator (commercial approximate compacted-depth coverage; not a product-specific engineering design)
- Kafka Granite: Standard Pathway Mix specification template (product/system scope, compacted thickness, subbase, undefined compaction-percentage basis and optional edging)